VUPPM500 KIT Build Thread

[quarternote]

Hi all!

I've just finished the three boards, but when I fasten the main board to the edge board, the 16-pin M/F connectors don't seat fully due to the length of the standoffs. It appears to barely make connection. Is this normal? If so, I'll continue. Next up is soldering the display board to the main board, then operation check and calibration.

PTyndall

[Joe Malone]

Hi all!

I've just finished the three boards, but when I fasten the main board to the edge board, the 16-pin M/F connectors don't seat fully due to the length of the standoffs. It appears to barely make connection. Is this normal? If so, I'll continue. Next up is soldering the display board to the main board, then operation check and calibration.

PTyndall

Hi do the 4 metal standoffs measure 12mm long??

Do you have a photo so I can see the problem?

[quarternote]

Hi do the 4 metal standoffs measure 12mm long??

Do you have a photo so I can see the problem?

The standoffs measure 12mm, but the 16p connector is only about 8mm high, causing a gap when mating to the other 16p connector. The issue is hard to see in the photos, but hopefully this makes sense...

https://share.icloud.com/photos/00a3PTNK8BCqAaQqCnbyNNPVg

https://share.icloud.com/photos/0e7rJcnXu1XaMRCMsTo-_8Dfw

PTyndall

[Joe Malone]

Hi do the 4 metal standoffs measure 12mm long??

Do you have a photo so I can see the problem?

The standoffs measure 12mm, but the 16p connector is only about 8mm high, causing a gap when mating to the other 16p connector. The issue is hard to see in the photos, but hopefully this makes sense...

https://share.icloud.com/photos/00a3PTNK8BCqAaQqCnbyNNPVg

https://share.icloud.com/photos/0e7rJcnXu1XaMRCMsTo-_8Dfw

PTyndall

That looks normal. The hard plug-in height is 11mm so 12mm only leaves 1mm gap which is fine as all pins should be pushed on to the sockets by a few millimetres

[sysxguy]

Hi, I have my unit built with adding the AES I/O remaining and the first meter test is failing. In the green mode, left Leds 21-40 (top) stay off, then in orange mode, these 20 leds are red and in red mode, it looks perfect. Any ideas where I could troubleshoot? Right side is 100%. I can upload a video and/or pics of the build. I have de-fluxed the boards as suggested and followed the great suggestions of adding the transistors after the boards are soldered together and solder the multipin connectors before the electrolytic caps.

TIA Andy

[Joe Malone]

Hi, I have my unit built with adding the AES I/O remaining and the first meter test is failing. In the green mode, left Leds 21-40 (top) stay off, then in orange mode, these 20 leds are red and in red mode, it looks perfect. Any ideas where I could troubleshoot? Right side is 100%. I can upload a video and/or pics of the build. I have de-fluxed the boards as suggested and followed the great suggestions of adding the transistors after the boards are soldered together and solder the multipin connectors before the electrolytic caps.

TIA Andy

Attach here or email me some well lit in focus photos so I can check the led bar soldering and soldering between the display and main pcb. Top and bottom photos of the main pcb to check the transistors as well.

[sysxguy]

Hi Joe, thanks, here ya go

tempImageNOmKuO.gif

tempImageh2sUIe.gif

[sysxguy]

nb the "solder whisker" closest to the transistor closest to the middle of the unit is actually a cat hair or perhaps a cat whisker reflecting and now removed.

and I got 10 more leds working (21-30) found an unsoldered pin that fixes that but that leaves the top left led module still to solve.

[sysxguy]

tempImageULu5hT.gif

Update: unlike the right side, testing between the 2 points circled gives an open circuit and if I jumper these points together, the unit passes the meter test.

[sysxguy]

Happy to report I now have the meter calibrated, with AES input working and installed in my rack!

best Andy

[Joe Malone]

Happy to report I now have the meter calibrated, with AES input working and installed in my rack!

best Andy

HI Andy Great to hear you got it all working. I was about to pull the original pcb artwork to check which track path was open circuit.

You can also connect to the Digital input VUPPM with bluetooth now encase you didn't notice. Also the toslink input also works.

[hasanova]

Hi,

On the Edge 500 R34 (10R) gets burned whenever I power on the 500 rack.

First time it happened I got weird symmetrical RED Led scheme on the VUPPM display. After several minutes all the lights dimmed. I took it out and saw that R34 was burned out completely.
Weird, since I have a rack full of them (10 slots) and I calibrated all of them.
I checked all the PCB's and placement of parts. Seems okay.

Cleaned the edge card and place a new 10R resistor. Moved it to another slot, same thing happened, but now immediately powered off when I saw the weird lights. Slightly burned R34.

Cleaned the edge card again, but this time placed two holders. Removed the card edge from the main PCB and checked the voltages. Placed a new 10R resistor. All is okay.

What should I check next? There is something causing R34 to burn up, on the main PCB.

Thnx

IMG_20250808_092441344_AE.jpg

[Joe Malone]

Hi,

On the Edge 500 R34 (10R) gets burned whenever I power on the 500 rack.

First time it happened I got weird symmetrical RED Led scheme on the VUPPM display. After several minutes all the lights dimmed. I took it out and saw that R34 was burned out completely.
Weird, since I have a rack full of them (10 slots) and I calibrated all of them.
I checked all the PCB's and placement of parts. Seems okay.

Cleaned the edge card and place a new 10R resistor. Moved it to another slot, same thing happened, but now immediately powered off when I saw the weird lights. Slightly burned R34.

Cleaned the edge card again, but this time placed two holders. Removed the card edge from the main PCB and checked the voltages. Placed a new 10R resistor. All is okay.

What should I check next? There is something causing R34 to burn up, on the main PCB.

Thnx

IMG_20250808_092441344_AE.jpg

First send me a clear top and bottom Photo of the main VUPPM pcb so I can check it over.

Was this just built or was it running ok for a while?

R34 is the fuse resistor for the 5v rail. If you run the edge pcbs by itself is the 7805 outputting 5v ok?

If so remove the CPU and retest to see if the 10R still burns or not ?

If it still burns it will be a solder short. Double check you have no solder shorts between the solder links joining the front display pcb and main pcb.

Let me know what you find.

[hasanova]

Hi, I didn't see your reaction. Must have notifications turned off.

I've just wrote a long reaction, but got logged off somehow.

Anyway, long story short:
One of the TL074 IC's had a pin bent inwards, under the body. This was not noticable when it was seated in the holder.

All voltages are correct now. LEDs working. Now, the only thing is that, because of the high current that went through, the pattern I described before is now visible, due to difference in brightness, haha! Must have aged quickly.

My OCD kicked in for a sec, but I still think it's too much hassle to try and replace all these LED displays

Thanks Joe,
H.

RED PPM with GREEN VU over the top.png

LOW brightness LED.png

HIGH brightness LED.png

[Joe Malone]

Hi, I didn't see your reaction. Must have notifications turned off.

I've just wrote a long reaction, but got logged off somehow.

Anyway, long story short:
One of the TL074 IC's had a pin bent inwards, under the body. This was not noticable when it was seated in the holder.

OK this would not burn the 5v rail 10R?

All voltages are correct now. LEDs working. Now, the only thing is that, because of the high current that went through, the pattern I described before is now visible, due to difference in brightness, haha! Must have aged quickly.

My OCD kicked in for a sec, but I still think it's too much hassle to try and replace all these LED displays

This will usually not be the led bars as near impossible to damage them all the same amount. Remove the CPU and check the 10 x 100R all measure correctly since the dull pattern repeats ever 10 leds. If they do test ok it will most likely be a damaged output pin on the CPU. As the led matrix is 10 x 16 (8 x Red 8 x Green). I have seen similar happen with shorts on the solder links between the main pcb and display pcb.