Electronics > Repair
Tektronix TDS2024 Oscilloscope - Repair Log
tautech:
Backlight transformer primary pin measurements in circuit. (last used working)
From edge of PCB
Measured with Smart Tweezers 1khz test frequency.
Pin 1-2 = 1.61k
Pin 5-6 = 1.61k
Pin 3&4 = common
Pins 2&5 - 3/4 = ~140 milliohm 28 uH
Secondary @ 1khz test frequency
403 ohms 366 mH
sean0118:
Thanks, I think your transformer might be similar, but just for the black and white display? I've only got 5 pins on the primary. Mine has two outputs, for either black and white or colour.
Anyway, I was pretty sure my transformer was cooked so I opened it in the hopes of being able to rewind it, but looks like the enamel has melted off the wire and fused together so cant unwind it to see how many turns there are.
Seems like an upgrade to an LED backlight might be a good idea. There's some very cheap kits on ebay, but the problem is they need an input between 9V and 28V. I've only got -4V, +3.3V, +6V and +35V. Could I put it across -4V and +6V? The -4V was used for the CCFL inverter so with that disabled it should have some headroom.
tautech:
No my TDS2012B is color display just like yours.
Backlight transformer on the PSU has 6 pins primary side and 3 pins secondary side.
If necessary I can remove it and get DMM measurements of the windings and inductance of each with my Smart Tweezers. As you have the wire gauge diameter calculating the wire length should be straightforward once the resistance is known.
sean0118:
--- Quote from: tautech on August 17, 2021, 10:09:54 am ---As you have the wire gauge diameter calculating the wire length should be straightforward once the resistance is known.
--- End quote ---
That's a good point, I am sort of tempted to try that to see if I can get it working. But I think this one's probably seen a lot of use, so the CCFL tube might be aged anyway. I think an LED strip might be the way to go, even if I have to design a custom driver. ;)
tautech:
--- Quote from: sean0118 on August 17, 2021, 10:59:55 am ---But I think this one's probably seen a lot of use, so the CCFL tube might be aged anyway.
--- End quote ---
If you can see the service menu it should list the total runtime IIRC.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version