Advantest R6245 - Dual-Channel SMU

[leighcorrigall]

Hello forum members,

I have a fairly unique instrument called the Advantest R6245 (acquired by ADCMT Inc. https://www.adcmt.com/en/company) that I purchased from a Korean eBay Seller. The datasheet has been attached for your convenience.


1) Luckily, the instrument is in good cosmetic condition apart from a rear bumper that was damaged during shipping. Unlike other SMUs there is no air filter, so I spent two solid days cleaning the instrument.
2) During the extensive cleaning process, I inspected the unit for signs of damage. It seems that the instrument was never opened because there are markings on every single screw head to indicate whether the part has been previously disassembled. Here are some signs of possible damage that I could see:



3) The fuse was missing when I first received the unit, so I found an appropriate North American fuse replacement (Littlefuse 0314005.HXP).
4) The fan runs when the power is switched ON, but nothing from the front panel display indicates. No display, no indicators from the switches.

The following posts will be a teardown of the entire instrument during the cleaning process.

[leighcorrigall]

Step A


1.   Remove the back bumper feet to slide the top and bottom panelling away from the chassis.
2.   After the removal of the chassis covers, there are two cover panels that come off with standardized screws.
3.   To remove the main control board, there are two shorter screws indicated by the circles of the previous step. These screws are slightly shorter and should be separated from the rest. Make note of where the ribbon cables are connected and begin to disconnect these from the main board.

[leighcorrigall]

Step B


4.   The screw to the left acts as a ground for the shielded ribbon cable in black that extends from the main control board to the front display panel.
5.   The back panel GPIB and I/O interface can be removed now.

[leighcorrigall]

Step C


6.   Further disassembly of the GPIB and I/O interface can be performed.
7.   This is a picture of the main control board, after the removal of the shield.

[leighcorrigall]

Step D


8.   The two other digital boards can be removed with pull levers on either side. Be careful to make note of which cables are associated with each board for reassembly. Due to the tight fits of each board, be certain not to accidentally damage the components during removal.

[leighcorrigall]

Step E


9.   The capacitor bank, located directly in front of the chassis, can be removed with a few standard screws. Adjacent to the first bank, there is an identical capacitor bank in the front corner that will be removed later. I labelled them left and right with a marker so as not to confuse them when reinstalling.
10.   Each SMU channel has a pair of boards. Remove the first unshielded set by lifting the pull lever and the metal bracket so that board can be removed upward. Be careful to remove the wire connected to each of these boards. The wire has been identified with a circle.

[leighcorrigall]

Step F


11.   The second part of each SMU channel can be extracted by removing the screw indicated by the circle and the metal bracket at the back of the instrument. Gently lift the shielded board to disconnect the bottom socket and then moving the board backwards to compensate for the front panel jacks. These shielded boards act as the interface with the device under test and hold the most sensitive components.
12.   At this time, the second capacitor bank (located in the front corner, next to the transformers) should be removed so that the wire bundles can be removed from their sockets, to access the main power supply and heat sink.

[leighcorrigall]

Step G


13.   Now that most of the boards have been removed, it is possible to remove the main power supply. There are four screws on the bottom of the chassis and four standard-sized screws at the back panel as indicated by the squares in the previous picture. Shown below are the top (left) and bottom (right) of this major component. It is comprised of four circuit boards, arranged to make maximum use of the two aluminum heat sink channels. Two board pairs seem to be near identical as with many of the other boards seen for the purpose of two independent SMU channels. I can show a teardown of this later, as it is a highly complex assembly.

[leighcorrigall]

Step H


14.   To approach the front panel, both the top and bottom panelling must be removed to access the four hidden side screws as shown with circles below. Remove the ribbon cables from the rest of the instrumentation. If it is desirable to completely remove the front panel from the rest of the chassis, one must disconnect the power switch either from the switch itself or by the fuse/terminal bar from underneath the chassis.

EDIT: There are an additional six screws to secure the front panel at the bottom (around the centre) and top (near the 2 SMU channels).

15.   There are three boards that make up the front panel, including the power module (left), a shielded vacuum display, and a keypad interface (right).

[leighcorrigall]

FIRMWARE: (untested)

EDIT: As the instrument has now turned on without any issues, I believe this firmware is working. Please backup your EPROMs before attempting these BIN files.

Step C

Step D

I have copied the firmware from the EPROMs of both digital boards (quoted) and have attached them here for others to use. At this point, I do not know what version they are or whether they are working. When I find out, I will update this post accordingly.

EDIT: The instrument displays the following message during bootup, which may indicate the firmware version
R6245 GPIB address = 17
Rev= D91, D01, D01

Note that the EPROM part numbers have been included as the prefix and the Advantest description has been included as a suffix.

[leighcorrigall]

As mentioned earlier,

The fan runs when the power is switched ON, but nothing from the front panel display indicates. No display, no indicators from the switches.

No service manual is available. The instruction manual is written in Japanese and it does not appear to have details about repairing or troubleshooting, other than sending it back to a service centre.

It appears that the instrument is either suffering from an overheating issue that burnt out components and/or a portion of the power supply is damaged. The internal fan operates, but there are multiple power supplies within the unit which might have failed (as indicated with the initial post images of what appears to be damage).

Inspecting the control board indicates that there are test points that can be measured:

Voltage measurements relative to ground :
TP1 – 0 (GND)
TP2 – 0.45 VDC (VCC) <--- Problem?
TP3 – 12.9 VDC <--- PASS
TP3E – 12.9 VDC <--- PASS

The EPROM M27C2001 VCC should be 5 DCV during operation. If this is true, then the supply voltage is significantly lower than it should be. From the attached image, can anyone confirm that the VCC is labelled TP2 and that it should be 5 V?

If it is the case, then the front power module might be the problem .

Here are some signs of possible damage that I could see:
(Attachment Link)

[serg-el]

Catalog 2007 and Expanded catalog and selection guide.

[leighcorrigall]

If it is the case, then the front power module might be the problem (Attachment Link) .

After the mains switch at the front, the line is fed into two labelled fuses underneath the rear transformer. They appear to be functioning correctly.



The front panel power supply module is directly connected to the rear transformer via two pairs of white (#1) and red (#2) wiretaps.

From the trace of the front panel power supply module, it appears that the colours are paired. This can be assumed because the connections are ordered to prevent mixing the white or red inputs if accidentally reversed. EDIT: I labelled the pins W and B because I am colourblind and assumed that the red wire was actually brown.

white wire pair: 20.8 VAC
red wire pair: 11.5 VAC

female input connector:
(white) (white) (---) (---) (red) (---) (red)

male input connector on the board:
(pin 6) (F2) (J3) (J3) (F1) (F1)

There are two fuses (F1 and F2) on the power supply module adjacent to the transformer hookup jack (male input connector). By inspection, there does not seem to be a filament bridging the terminals of F1. This has been confirmed by measuring the resistance across the terminals from underneath the circuit board. The identifiers on the top of the fuse are as follows:

FRPU
5A
ROYAL




The datasheet for this part has been attached to this post and matches the dimensions and description from the board.
 royal-fuse-HF-8.pdf (188.03 kB - downloaded 212 times.)

I may have identified one of the problems with the unresponsive main control board and front panel.

Before replacing the fuse, I should determine whether the transformers are outputting the correct voltages by finding the specifications online for these particular units. This will require removing the main control board to read the printed identifiers on the tightly mounted transformers.

[leighcorrigall]

Before replacing the fuse, I should determine whether the transformers are outputting the correct voltages by finding the specifications online for these particular units. This will require removing the main control board to read the printed identifiers on the tightly mounted transformers.

The identifier for the rear transformer (1 of 2) that provides power to the front panel power supply module is as follows:

LTP-R6245CA
OBOU
NIHON KOHDEN

Unfortunately, there doesn't seem to be much information available for this specialized transformer.

[leighcorrigall]

Catalog 2007 and Expanded catalog and selection guide.

The datasheet was already posted.

[leighcorrigall]

FRPU
5A
ROYAL

A substitute part is available from Littlefuse. See attachment (273 and 274 Series). There are likely cheaper alternatives, but I wanted to find something that matched the original.

[leighcorrigall]

Well, there it is. I just turned a broken instrument into 5k USD with a fuse and a little investigation. 

I will continue posting more details about the instrument in the future for anyone that is interested in this type of test equipment.

Thank you.

[leighcorrigall]

Luckily, the instrument is in good cosmetic condition apart from a rear bumper that was damaged during shipping.

Attached is a CAD model of the rear bumper that was severely damaged during shipping from Korea. Keep in mind that this is one of two isomers needed to produce all four bumpers. In other words, these are mirror images of each other.

The fastener is comprised of the following assembly:

M4 x 0.7 mm pan rounded Phillips screw, 25 mm in length
flat washer with an 8 mm OD and a thickness of 0.5 mm
split lock washer with a 6.5 mm OD and a thickness of 1 mm

[leighcorrigall]

Section 11 - Theory of Operations, ADCMT R6245 Instruction Manual (with English translations)

The following figures have been provided to give the EEVBlog Forum members an opportunity to review the basic operational principles of this instrument.

Figure 11-1 - Block Diagram
Figure 11-2 - SMU Block Diagram

Note: There are brief descriptions that are in Japanese that I do not have the ability to effectively translate.

[leighcorrigall]

Rear Filter Cage

Due to the lack of air quality control for this instrument, I decided to design an air filter for the rear exhaust. It should be easily reproducible with a 3D printer.

EDIT: This filter cage is too long. I have modified the design so that it should fit now. Please see the next iteration below.

The filter material can be purchased from DigiKey and cut to size:
https://www.digikey.ca/en/products/detail/orion-fans/LFG172BF-PK/4741169

[leighcorrigall]

Axial Fan Replacement

The original Brushless 12 DCV Sanyo Denki 109R1212H101 120x120x38 mm fan, which includes a pulse sensor, inside the R6245 is about 28 years old and still runs. However, I plan on replacing this obsolete fan with the 9WG1212E101-E from the same company having a 15 % improvement in airflow [3.34 m^3/min]. Note that the 9WG1212G101-E has slightly better performance (34 %), but I  do not know the upper current threshold of the fan circuit. To be safe, I went with similarly matched specifications and will reuse the 3-pin socket from the original.

The plan is to redirect the air intake from the rear of the unit to utilize a fan filter previously posted about. This way, I should be able to avoid cleaning the unit from contaminants. When I received this unit, it was the dirtiest thing I have ever had to clean.

EDIT: The fan replacement is noticeably louder. This may offend some people, especially if you ride this down a small-town street dressed in leather.

[42Khz]

Before replacing the fuse, I should determine whether the transformers are outputting the correct voltages by finding the specifications online for these particular units. This will require removing the main control board to read the printed identifiers on the tightly mounted transformers.

The identifier for the rear transformer (1 of 2) that provides power to the front panel power supply module is as follows:

LTP-R6245CA
OBOU
NIHON KOHDEN

Unfortunately, there doesn't seem to be much information available for this specialized transformer.

Thanks for the detailed teardown of this unit!

I'm wondering, can the transformers be rewired for all different mains input voltage options? Specifically European mains.
I couldn't quite make that out from your pictures and unfortunately I can't find any schematics either.

[leighcorrigall]

Thanks for the detailed teardown of this unit!

I'm wondering, can the transformers be rewired for all different mains input voltage options? Specifically European mains.
I couldn't quite make that out from your pictures and unfortunately, I can't find any schematics either.

The instruments are made for specific electrical mains according to the back panel (photo attached). You might be able to rewire an American/Japanese system to work in Europe given enough time and patience. Keep in mind that the volume available for this kind of job is extremely limited. The designers were extremely precise with their layout. Also, there are 5 fuses within the instrument that would need to be considered when converting this instrument to an alternate power system. Two are soldered to the front panel power supply. Two are below the transformers. One is located on the back panel as a panel fuse holder.

After the two secondary fuses, most of the transformer taps of both transformers (two-channels) are connected directly to the bottom distribution board. You might have to replace the transformers to allow for 220 VAC, but I do not have much experience with such things.

If you need more pictures, I can try to accommodate. Please give me an idea of what you want photographed and next time I disassemble the instrument, I will take them.

As for the schematics, you won't find them easily unless you are literate in Japanese and can find some noble person on the web that has unofficially posted them. The company (ADCMT) only provides an instruction manual and a GPIB guide book in Japanese. So far, I do not have any schematics, other than the block diagrams provided above.

I got lucky with my instrument because everything seems to function properly so far. Some of the keys are a bit sticky, but I think I can clean them out with some isopropanol once I have time.

[42Khz]

Thanks for the detailed teardown of this unit!

I'm wondering, can the transformers be rewired for all different mains input voltage options? Specifically European mains.
I couldn't quite make that out from your pictures and unfortunately, I can't find any schematics either.

The instruments are made for specific electrical mains according to the back panel (photo attached). You might be able to rewire an American/Japanese system to work in Europe given enough time and patience. Keep in mind that the volume available for this kind of job is extremely limited. The designers were extremely precise with their layout. Also, there are 5 fuses within the instrument that would need to be considered when converting this instrument to an alternate power system. Two are soldered to the front panel power supply. Two are below the transformers. One is located on the back panel as a panel fuse holder.

After the two secondary fuses, most of the transformer taps of both transformers (two-channels) are connected directly to the bottom distribution board. You might have to replace the transformers to allow for 220 VAC, but I do not have much experience with such things.

If you need more pictures, I can try to accommodate. Please give me an idea of what you want photographed and next time I disassemble the instrument, I will take them.

As for the schematics, you won't find them easily unless you are literate in Japanese and can find some noble person on the web that has unofficially posted them. The company (ADCMT) only provides an instruction manual and a GPIB guide book in Japanese. So far, I do not have any schematics, other than the block diagrams provided above.

I got lucky with my instrument because everything seems to function properly so far. Some of the keys are a bit sticky, but I think I can clean them out with some isopropanol once I have time.

Thanks for your detailed response!
Yes I noticed the options, the datasheet even says you have to specify which one you want at the time of ordering.

Replacing the fuses shouldn't be too difficult. I noticed the transformer in one of your photos has a label "120V", which got me curious as to whether it perhaps also has a 230V or 240V tap.
Or perhaps two 120V windings that can be configured either in parallel for 120V mains or in series for 240V mains, like in e.g. the HP 3456A. The Advantest TR6142 does seem to have some similar configurability.

I'd rather not have to swap out the transformers, I'm guessing it would be quite difficult and expensive to find suitable replacements.
If you do ever take your unit apart again, could check the labeling on the transformers and whether they can be reconfigured?

They do seem like very nice instruments (which got me interested in the first place). Congrats on your score!
I might try to figure out the details of the IV clamp in the block diagram you posted.

[leighcorrigall]

Rear Filter Cage

Due to the lack of air quality control for this instrument, I decided to design an air filter for the rear exhaust. It should be easily reproducible with a 3D printer.

The filter material can be purchased from DigiKey and cut to size:
https://www.digikey.ca/en/products/detail/orion-fans/LFG172BF-PK/4741169

An updated version of the filter cage has been provided. This should fit better than the last iteration. I am used to CNC machining tolerances, so I got a bit carried away.