Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

nope, I am to get a replica of an Apple 2e board for like 20 bucks. I thought, if I am a retro computer nut, I might just as well ...

So what... like the inverse function of a MAME console?

Next you'll need one of those old analog joysticks I found at the Thrift a while back...

mnem
 

[Saskia]

Whuf... is it really enuf better than a RX580/590 to be worth that kindof money? Even Linus couldn't figure out what the fuck NV was shooting for with that bastard child.

Probably why they never bothered to make it themselves, but left the whole shittin' mess for their channel partners to produce and bring to market.

mnem
 

it's mini-itx, as fast as a 1070 and a lot faster than my 1060@3GB which has problems at 4k. My RX590 went belly up and the dealer just refunded it instead of replacing it. Now I do have a 2070 that is also belly up, but I'll need to wait for replacement to be received while sitting on a number of mainboards, cases, PSUs that are collecting dust and need to be moved out.
Graphics cards being stoopeed expensive during lock down my chances of flipping a PC are higher if I can mount a not so over the top graphics card. Which is exactly what the 1660ti is.
also, it fits into an ITX case which means I can build a reasonably fast ITX system for a fair amount of money (especially as I already have the case, a PSU, an AIO water cooling sitting here.

Just combining stuff out of my inventory to kick it out of the door (and provide fellow TEA members with good hw for a very reasonable price, if they want it).

[Saskia]

nope, I am to get a replica of an Apple 2e board for like 20 bucks. I thought, if I am a retro computer nut, I might just as well ...

So what... like the inverse function of a MAME console?

Next you'll need one of those old analog joysticks I found at the Thrift a while back...

mnem
 

umm, just for fun. want to see it work, then try to do it in fpga.
see it as an exercise. If I can put an Apple 2 into an FPGA I should have grocked the principals of how to do it.
and for 20 bucks, well, WCPGW ?

[mnementh]

https://i.imgur.com/WVXlXga.mp4

 

mnem

[mnementh]

Whuf... is it really enuf better than a RX580/590 to be worth that kindof money? Even Linus couldn't figure out what the fuck NV was shooting for with that bastard child.

Probably why they never bothered to make it themselves, but left the whole shittin' mess for their channel partners to produce and bring to market.

mnem
 

it's mini-itx, as fast as a 1070 and a lot faster than my 1060@3GB which has problems at 4k. My RX590 went belly up and the dealer just refunded it instead of replacing it. Now I do have a 2070 that is also belly up, but I'll need to wait for replacement to be received while sitting on a number of mainboards, cases, PSUs that are collecting dust and need to be moved out.
Graphics cards being stoopeed expensive during lock down my chances of flipping a PC are higher if I can mount a not so over the top graphics card. Which is exactly what the 1660ti is.
also, it fits into an ITX case which means I can build a reasonably fast ITX system for a fair amount of money (especially as I already have the case, a PSU, an AIO water cooling sitting here.

Just combining stuff out of my inventory to kick it out of the door (and provide fellow TEA members with good hw for a very reasonable price, if they want it).

I get it... you weren't looking for one per se, just something approx 1070-ish at the right price point in the right form-factor. I understand having more crap than you know what to do with... I need to get rid of a few shedloads myself so I can stop paying storage. 

mnem
"Tonight, the zeroes are singing for you-u-u-u...."

[0culus]

I pulled out the 7904 power supply...it's ticking. Found one shorted cap on the rectifier board, removed it, but it's still ticking (though the front panel lamps are lighting up briefly with each pulse now). The 7904 power supply service document leads me to believe that the inverter controller IC is toast based on the evidence of how it is behaving with the shorted cap removed. I think my next move will be to at a minimum replace all the tantalum caps and try to find the IC (Tek custom, of course).

[Saskia]

@mnementh yep, u nailed it.

@Oculus good luck

@med very nice as always.

[mnementh]

I pulled out the 7904 power supply...it's ticking. Found one shorted cap on the rectifier board, removed it, but it's still ticking (though the front panel lamps are lighting up briefly with each pulse now). The 7904 power supply service document leads me to believe that the inverter controller IC is toast based on the evidence of how it is behaving with the shorted cap removed. I think my next move will be to at a minimum replace all the tantalum caps and try to find the IC (Tek custom, of course).

I'd continue on the basis that there is still something shorted; my troubleshooting here is usually to connect a meter with grabbits to each rail in turn, and measure in MIN-MAX mode while it powers up. Look for one that still doesn't try to come up when it turns on or with the tick cycles. Sometimes the difference is as small as one rail only comes up to 1-2 volts on MIN-MAX while the others come up to 50% or less of rated voltage.

If all of them seem to come up to roughly the same percentage of rated voltage before going into shutdown, that's when I usually start looking in the controller or pre-reg sections.

If you've done this troubleshooting and are still at this point, disregard and assume it's just for those playing along at home.

mnem
 

[bd139]

@bd just picked up a 1660 TI for 190 locally. Has ITX format, so it's small, running too hot, but fits in the crowded case.

Not a bad price. Sell it here for 300, then buy yourself a 3060 locally to you 

[Saskia]

People who are of the opinion that Covid is like the Flu needs to see this, it is much worse than any flu could be and the authorities on this film, in Italy made the UK government aware of it very early on and yet, we seem to have ignored them 

It is criminal really the way that we buried our heads in the sand of this virus and still continue to do. Gagging the experts, the NHS and despite the NHS pleading that they do something to shut up those that continue to claim that it is all a hoax etc. This week they have been holding demonstrations outside of hospitals where people are dieing the virus and still the authorities do nothing about shutting these morons down, the same goes for the 5G brigade as well, what will it take before these people are dealt with, they are causing others to suffer immensely. Is now the way of the world, where people are happy to see others suffer?

while I absolutely concur that government (yours, ours, almost all) completely fucked up I do not think that Covid is any worse than any real flu. Flu can kill you just as dead as covid, just as fast as covid, it's just the mechanism that is slightly different.
https://www.scientificamerican.com/article/how-does-the-flu-actually-kill-people/

Please don't confuse the real flu with the common cold. Just because there is not as much hubbub about the flu does not mean it's harmless. On the contrary. A couple of years ago we had about 25000 dead in germany due to the flu. They just did not call it pandemic, however the number of dead is about the same as with Covid. The main difference is that apparently covid is a lot easier to contract than the flu.

I am not saying that Covid is harmless. I am saying: avoid covid, avoid the flu.

[mnementh]

@bd just picked up a 1660 TI for 190 locally. Has ITX format, so it's small, running too hot, but fits in the crowded case.

Not a bad price. Sell it here for 300, then buy yourself a 3060 locally to you 

Where? Even with the currency conversion, you'd need to sell almost two of them to get even a used Founder's Edition 3060.

Alternately, DROOL...!!! https://solutions.nextcomputing.com/product/edge-xti-data-science-deep-learning-workstation-intel-xeon-gold-6234-192gb-ram-1024gb-ssd-dual-rtx-8000-gpus/

mnem
 

[Saskia]

Thanks, I'll pass. Got 4 Tesla P100 right now, one host w64 cores128 GB, the other one with 256gb. Snuff to do a bit of tensor flow...

[tautech]

I pulled out the 7904 power supply...it's ticking. Found one shorted cap on the rectifier board, removed it, but it's still ticking (though the front panel lamps are lighting up briefly with each pulse now). The 7904 power supply service document leads me to believe that the inverter controller IC is toast based on the evidence of how it is behaving with the shorted cap removed. I think my next move will be to at a minimum replace all the tantalum caps and try to find the IC (Tek custom, of course).

Shit simple to test with an external PSU and another scope....just do it with the 7904 all powered down.
Does the IC have a VCC spec ? Drive it at VCC and scope its output.

[Specmaster]

That's one reason I quit recently. It's not even worth spending the time defending yourself from the fucktards. Just walk.

Quite agree, thats how I came to be retired, it became pretty obvious that there was a malicious campaign against me by the Regional Manager, New Sales Director and I had managed to catch sight of some emails going back and forth and that they were getting the new MD elect to also turn against me that I decided it was pointless fighting for my job as they kept trumping up one thing after another, so I took legal advice and walked, leaving the legal teams to fight it out.

I still feel a little bitter about the way that the RM effectively threw me under the bus to protect himself but like Saskia, I did have a habit of speaking out if I thought that a bad decision had been made and many times I have been proven to be right, one such occasion was just after the new sales director had been appointed, a decision by the MD after a sustained campaign by the Regional and at that time he was also the NSM, almost pushed the company to the wall, a year later, I walked after deciding I did not deserve the shit and was not putting up with it any longer, fucktards is about right.

[Specmaster]

People who are of the opinion that Covid is like the Flu needs to see this, it is much worse than any flu could be and the authorities on this film, in Italy made the UK government aware of it very early on and yet, we seem to have ignored them 

It is criminal really the way that we buried our heads in the sand of this virus and still continue to do. Gagging the experts, the NHS and despite the NHS pleading that they do something to shut up those that continue to claim that it is all a hoax etc. This week they have been holding demonstrations outside of hospitals where people are dieing the virus and still the authorities do nothing about shutting these morons down, the same goes for the 5G brigade as well, what will it take before these people are dealt with, they are causing others to suffer immensely. Is now the way of the world, where people are happy to see others suffer?

while I absolutely concur that government (yours, ours, almost all) completely fucked up I do not think that Covid is any worse than any real flu. Flu can kill you just as dead as covid, just as fast as covid, it's just the mechanism that is slightly different.
https://www.scientificamerican.com/article/how-does-the-flu-actually-kill-people/

Please don't confuse the real flu with the common cold. Just because there is not as much hubbub about the flu does not mean it's harmless. On the contrary. A couple of years ago we had about 25000 dead in germany due to the flu. They just did not call it pandemic, however the number of dead is about the same as with Covid. The main difference is that apparently covid is a lot easier to contract than the flu.

I am not saying that Covid is harmless. I am saying: avoid covid, avoid the flu.

Oh I know that Flu can be very deadly, nobody has to convince me of that, I lost my Sister to Asian Flu when I was 12 years old and well aware of the Flu jabs every winter to try and prevent it and have lived through many mutations of it, but Covid is extremely debilitating and savage and  spreads like wildfire.

[0culus]

I pulled out the 7904 power supply...it's ticking. Found one shorted cap on the rectifier board, removed it, but it's still ticking (though the front panel lamps are lighting up briefly with each pulse now). The 7904 power supply service document leads me to believe that the inverter controller IC is toast based on the evidence of how it is behaving with the shorted cap removed. I think my next move will be to at a minimum replace all the tantalum caps and try to find the IC (Tek custom, of course).

I'd continue on the basis that there is still something shorted; my troubleshooting here is usually to connect a meter with grabbits to each rail in turn, and measure in MIN-MAX mode while it powers up. Look for one that still doesn't try to come up when it turns on or with the tick cycles. Sometimes the difference is as small as one rail only comes up to 1-2 volts on MIN-MAX while the others come up to 50% or more of rated voltage.

If all of them seem to come up to roughly the same percentage of rated voltage before going into shutdown, that's when I usually start looking in the controller or pre-reg sections.

If you've done this troubleshooting and are still at this point, disregard and assume it's just for those playing along at home.

mnem
 

Good idea, though actually a VOM is a better choice as my Fluke 87 seems to be unable to latch very well in min max mode (maybe the rep rate is too fast?). I pulled out the trusty Simpson 260 and it appears they are all rising to about the same (rather small) % of rated voltage before shutting down.

I pulled out the 7904 power supply...it's ticking. Found one shorted cap on the rectifier board, removed it, but it's still ticking (though the front panel lamps are lighting up briefly with each pulse now). The 7904 power supply service document leads me to believe that the inverter controller IC is toast based on the evidence of how it is behaving with the shorted cap removed. I think my next move will be to at a minimum replace all the tantalum caps and try to find the IC (Tek custom, of course).

Shit simple to test with an external PSU and another scope....just do it with the 7904 all powered down.
Does the IC have a VCC spec ? Drive it at VCC and scope its output.

Will probably be the next thing I try. Need to go have a squint at the schematic....

[Specmaster]

Looking wonderful Med, did you have any problems with excessive noise being introduced at all with the longer leads?

No, those leads are not grounds, they are the B+ lines. No issues with noise.

Hmm, I would have thought that noise would have been introduced on the B+ lines and noise and ripple etc are then filtered through the caps to ground and the chassis was effectively a screen, a Faraday cage of sorts keeping externally introduced noise from reaching the sensitive circuit within the chassis, hence why some tubes / valves have metal screening caps which are connected to chassis ground?

[Cerebus]

while I absolutely concur that government (yours, ours, almost all) completely fucked up I do not think that Covid is any worse than any real flu. Flu can kill you just as dead as covid, just as fast as covid, it's just the mechanism that is slightly different.
https://www.scientificamerican.com/article/how-does-the-flu-actually-kill-people/

Please don't confuse the real flu with the common cold. Just because there is not as much hubbub about the flu does not mean it's harmless. On the contrary. A couple of years ago we had about 25000 dead in germany due to the flu. They just did not call it pandemic, however the number of dead is about the same as with Covid. The main difference is that apparently covid is a lot easier to contract than the flu.

I am not saying that Covid is harmless. I am saying: avoid covid, avoid the flu.

The numbers don't bear that out. Covid-19 typical case fatality ratio 2.7% (all ages, modal, individual figures quite variable from country to country), influenza CFR 0.14% (all ages, US Flu season 2017-2018). Deaths per 100,000 population - Covid-19 US to date 107 deaths per 100,000, US Flu season 2017-2018 18.7 deaths per 100,000.

Conclusion: Covid-19 is a significantly more deadly disease than annual influenza, a random person is about 19 times (most western countries) more likely to die if they catch covid than if they catch flu.

At the population level Covid has been killing nearly 6 times as many people in the US as flu did in the 2017-2018 flu season (figures for other western countries have been broadly similar). Influenza infection rates, and hence mortality, are probably lower than might otherwise be because of annual vaccination programmes of the elderly and vulnerable against flu. Annual influenza vaccination coverage is a very creditable ~50% of the US general population and about 45% for the vulnerable and 73% for the over 65s in the UK. Obviously vaccination has no effect on case fatality ratios.

Sources: https://coronavirus.jhu.edu/data/mortality, https://www.cdc.gov/flu/about/burden/2017-2018.htm.

[0culus]

I pulled out the 7904 power supply...it's ticking. Found one shorted cap on the rectifier board, removed it, but it's still ticking (though the front panel lamps are lighting up briefly with each pulse now). The 7904 power supply service document leads me to believe that the inverter controller IC is toast based on the evidence of how it is behaving with the shorted cap removed. I think my next move will be to at a minimum replace all the tantalum caps and try to find the IC (Tek custom, of course).

I'd continue on the basis that there is still something shorted; my troubleshooting here is usually to connect a meter with grabbits to each rail in turn, and measure in MIN-MAX mode while it powers up. Look for one that still doesn't try to come up when it turns on or with the tick cycles. Sometimes the difference is as small as one rail only comes up to 1-2 volts on MIN-MAX while the others come up to 50% or more of rated voltage.

If all of them seem to come up to roughly the same percentage of rated voltage before going into shutdown, that's when I usually start looking in the controller or pre-reg sections.

If you've done this troubleshooting and are still at this point, disregard and assume it's just for those playing along at home.

mnem
 

Good idea, though actually a VOM is a better choice as my Fluke 87 seems to be unable to latch very well in min max mode (maybe the rep rate is too fast?). I pulled out the trusty Simpson 260 and it appears they are all rising to about the same (rather small) % of rated voltage before shutting down.

I pulled out the 7904 power supply...it's ticking. Found one shorted cap on the rectifier board, removed it, but it's still ticking (though the front panel lamps are lighting up briefly with each pulse now). The 7904 power supply service document leads me to believe that the inverter controller IC is toast based on the evidence of how it is behaving with the shorted cap removed. I think my next move will be to at a minimum replace all the tantalum caps and try to find the IC (Tek custom, of course).

Shit simple to test with an external PSU and another scope....just do it with the 7904 all powered down.
Does the IC have a VCC spec ? Drive it at VCC and scope its output.

Will probably be the next thing I try. Need to go have a squint at the schematic....

I found a datasheet for the IC on tekwiki, but it would seem that it is indeed, dead. No outputs at all, and sometimes it randomly started acting like it was shorting, drawing a lot of current and getting very hot.

[beanflying]

Road Trip to the middle of nowhere. Might be worth dropping the seller a message if anyone is keen eBay auction: #154269650090 $1 USD pickup only.

[tautech]

I found a datasheet for the IC on tekwiki, but it would seem that it is indeed, dead. No outputs at all, and sometimes it randomly started acting like it was shorting, drawing a lot of current and getting very hot.

Bugger.
Any chance that IC can be replaced with just a generic SMPS IC ?

[med6753]

I pulled out the 7904 power supply...it's ticking. Found one shorted cap on the rectifier board, removed it, but it's still ticking (though the front panel lamps are lighting up briefly with each pulse now). The 7904 power supply service document leads me to believe that the inverter controller IC is toast based on the evidence of how it is behaving with the shorted cap removed. I think my next move will be to at a minimum replace all the tantalum caps and try to find the IC (Tek custom, of course).

I'd continue on the basis that there is still something shorted; my troubleshooting here is usually to connect a meter with grabbits to each rail in turn, and measure in MIN-MAX mode while it powers up. Look for one that still doesn't try to come up when it turns on or with the tick cycles. Sometimes the difference is as small as one rail only comes up to 1-2 volts on MIN-MAX while the others come up to 50% or more of rated voltage.

If all of them seem to come up to roughly the same percentage of rated voltage before going into shutdown, that's when I usually start looking in the controller or pre-reg sections.

If you've done this troubleshooting and are still at this point, disregard and assume it's just for those playing along at home.

mnem
 

Good idea, though actually a VOM is a better choice as my Fluke 87 seems to be unable to latch very well in min max mode (maybe the rep rate is too fast?). I pulled out the trusty Simpson 260 and it appears they are all rising to about the same (rather small) % of rated voltage before shutting down.

I pulled out the 7904 power supply...it's ticking. Found one shorted cap on the rectifier board, removed it, but it's still ticking (though the front panel lamps are lighting up briefly with each pulse now). The 7904 power supply service document leads me to believe that the inverter controller IC is toast based on the evidence of how it is behaving with the shorted cap removed. I think my next move will be to at a minimum replace all the tantalum caps and try to find the IC (Tek custom, of course).

Shit simple to test with an external PSU and another scope....just do it with the 7904 all powered down.
Does the IC have a VCC spec ? Drive it at VCC and scope its output.

Will probably be the next thing I try. Need to go have a squint at the schematic....

I found a datasheet for the IC on tekwiki, but it would seem that it is indeed, dead. No outputs at all, and sometimes it randomly started acting like it was shorting, drawing a lot of current and getting very hot.

I fell asleep and missed all the excitement. I never had to venture into the Inverter board side of things with my 7904 so you are in uncharted territory.  All my troubles were on the Rectifier/Regulator boards.

I'll bet the shorted tant was 47uF...right? 

[med6753]

https://i.imgur.com/WVXlXga.mp4

 

mnem

That will buff out. 

[0culus]

I pulled out the 7904 power supply...it's ticking. Found one shorted cap on the rectifier board, removed it, but it's still ticking (though the front panel lamps are lighting up briefly with each pulse now). The 7904 power supply service document leads me to believe that the inverter controller IC is toast based on the evidence of how it is behaving with the shorted cap removed. I think my next move will be to at a minimum replace all the tantalum caps and try to find the IC (Tek custom, of course).

I'd continue on the basis that there is still something shorted; my troubleshooting here is usually to connect a meter with grabbits to each rail in turn, and measure in MIN-MAX mode while it powers up. Look for one that still doesn't try to come up when it turns on or with the tick cycles. Sometimes the difference is as small as one rail only comes up to 1-2 volts on MIN-MAX while the others come up to 50% or more of rated voltage.

If all of them seem to come up to roughly the same percentage of rated voltage before going into shutdown, that's when I usually start looking in the controller or pre-reg sections.

If you've done this troubleshooting and are still at this point, disregard and assume it's just for those playing along at home.

mnem
 

Good idea, though actually a VOM is a better choice as my Fluke 87 seems to be unable to latch very well in min max mode (maybe the rep rate is too fast?). I pulled out the trusty Simpson 260 and it appears they are all rising to about the same (rather small) % of rated voltage before shutting down.

I pulled out the 7904 power supply...it's ticking. Found one shorted cap on the rectifier board, removed it, but it's still ticking (though the front panel lamps are lighting up briefly with each pulse now). The 7904 power supply service document leads me to believe that the inverter controller IC is toast based on the evidence of how it is behaving with the shorted cap removed. I think my next move will be to at a minimum replace all the tantalum caps and try to find the IC (Tek custom, of course).

Shit simple to test with an external PSU and another scope....just do it with the 7904 all powered down.
Does the IC have a VCC spec ? Drive it at VCC and scope its output.

Will probably be the next thing I try. Need to go have a squint at the schematic....

I found a datasheet for the IC on tekwiki, but it would seem that it is indeed, dead. No outputs at all, and sometimes it randomly started acting like it was shorting, drawing a lot of current and getting very hot.

I fell asleep and missed all the excitement. I never had to venture into the Inverter board side of things with my 7904 so you are in uncharted territory.  All my troubles were on the Rectifier/Regulator boards.

I'll bet the shorted tant was 47uF...right? 

Oh yeah...it's cute and even blue.  I think the IC might actually be working though...the inverter stop output signal is, in fact, present and runs exactly in time with the ticking. I'm not sure what else it could be at this point. Maybe more shorted caps buried inside?

[med6753]

I found a datasheet for the IC on tekwiki, but it would seem that it is indeed, dead. No outputs at all, and sometimes it randomly started acting like it was shorting, drawing a lot of current and getting very hot.

Bugger.
Any chance that IC can be replaced with just a generic SMPS IC ?

Later Tek designs, like the 2430,  did indeed use a generic and readily available SMPS controller IC.