PLD getting hot - Page 1
Forum section: electronics / repair

author: kraka
author_rank: Contributor
timestamp: September 24, 2024, 10:54:28 pm
content: I have not electronics background but after two technicians refuse to repair my Audio Card, (maybe they did not have time, or they underestimate my card, although it is an excellent one), i decided to try, at least, fix it.My Audio Card (PCI type) stopped having sound. It is the EMU APS.While i was trying to examine it, i notice that two components that are located very close to each other,1) the ALTERA EPM 7064S1C44-10 BFB249919 EMU98 9946 and2) the P98AB VT244are getting hot very quickly. They are getting hot even if the Card snap onto the motherboard, and Windows boots up.As i was told from somebody with a good background in electronics :1)The '244' is almost certainly an interface to a black socket beside it, which is a connector to the Game joystick. That device is written at one side and read on the other, the input side has no capability to read anything back so if i am not using the black connector i can probably remove the IC to eliminate the problem with no adverse effects. Indeed i will not use the Joystick connector, so here i have not a problem.2) the ALTERA device is a programmable logic device (PLD), and my only option would be to buy one from the card manufacturer and the chances of them carrying spares, even when in production, is very slim. Usually cards like that are sent out to sub-contracted assembly plants and the named manufacturer never sees any individual parts. It is normal for them to run warm.But even if i found the ALTERA, shouldn't program it with the firmware before I replace the old one, otherwise it won't work ? But it is impossible to program it. So my only change is to be true what i have been told in 1) and especially the last sentence : " It is normal for them to run warm"Is this truth ? (about the normal worming ?)Ι attached a photo of my cardBig red arrow point to the ALTERA and small arrow to the P98AB VT244(Any suggestion or idea for how i can fix it, or what procedure to follow, will be welcome)

author: fzabkar
author_rank: Super Contributor
timestamp: September 24, 2024, 11:44:31 pm
content: I agree that the VT244 chip could be removed without affecting your usage of the card.https://datasheet.octopart.com/74LVT244MTC-Fairchild-datasheet-7551912.pdfThe PLD will be a problem:https://edg.uchicago.edu/~bogdan/dirac/doc/parts/m7000.pdfQuote

author: kraka
author_rank: Contributor
timestamp: September 25, 2024, 12:59:39 pm
content: Next days i will remove the VT244 and probably i will understand if the ALTERA is broken, but until then, is there a chance there is, on my Card or inside the ALTERA, a self-protect for current remain in safe values ?I do not know if this is the correct way, but i measure all pins of the ALTERA (on board) and find no short to the Ground (except the GND pins).

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 25, 2024, 03:28:09 pm
content: 1) You haven't defined "hot". If you can keep your finger on it without burning it, it's probably not that "hot".2) The Altera part is programmed. Replacing it with a blank probably won't help.

author: dferyance
author_rank: Regular Contributor
timestamp: September 25, 2024, 04:42:09 pm
content: Certainly a part getting hot quickly could be a sign of where the fault is, but it also isn't definitive. Looks like that card has an external interface box and based off the placement of the CPLD, it could be used for driving that. Best to figure out what does or doesn't work to narrow things down. You indicate no sound, but I assume the PCI device is still recognized right? So possibly something with the audio pathway. I see a headphones connector on it, maybe try different ways of getting sound out of it in case one way works and another doesn't.I'm just concerned that you may put too much effort or possibly cause damage in an area that isn't at fault. I wouldn't expect the CPLD being responsible for DAC or audio analog circuits. So if the headphone plug works but the other audio jacks don't, it is likely somewhere else that is failing. If it fails for everything, then yeah it could be part of the problem.

author: DaJMasta
author_rank: Super Contributor
timestamp: September 25, 2024, 06:56:34 pm
content: Quote from: Ice-Tea on September 25, 2024, 03:28:09 pmThis. Also, check voltages for it. A wonky rail can cause heating too.

author: fzabkar
author_rank: Super Contributor
timestamp: September 25, 2024, 08:07:19 pm
content: Have you measured the output voltages at VR1 - VR5 ?

author: kraka
author_rank: Contributor
timestamp: September 25, 2024, 09:12:22 pm
content: Quote from: Ice-Tea on September 25, 2024, 03:28:09 pmThis is good news.Now i am far away from my Card. Next days I will examine how hot is the "hot". The "finger burning" sounds a good technique.thanks

author: kraka
author_rank: Contributor
timestamp: September 25, 2024, 09:36:32 pm
content: Quote from: dferyance on September 25, 2024, 04:42:09 pmYes, the Card has an external interface box (E-Drive), with input jacks for Guitars, Mics etc, and placed in front of the PC (unlike the mentioned above E-Card, that located on board and its jacks comes out on the back of the computer). These two Cards (the E-Card and the E-Drive) are connected with a 20 pin cable through the black socket you can see above the ALTERA. The , two right sockets are for Game Joystick and Expand Connections and i do not need them.Yes, the PCI is recognized. I check the Audio Pathway. Believe me, i check everything related to other things than the card itself (hardware). Now and for 1-2 years i made all the combinations related with drivers, OS's, Windows settings, BIOS settings etc. I have install and reinstall , many times, all the Windows versions i could find, from Card's native Win95 - Win 98 to 2000, Vista, XP, ME, 7.When i bought it (second hand, before 6-7 years) worked OK with my PC on WinXP using modified drivers.Maybe the issue related to a faulty (expensive, 650Watt) PSU i have bought and now it is removed and replace with a chipper but more reliable (450Watt).

author: kraka
author_rank: Contributor
timestamp: September 25, 2024, 09:46:07 pm
content: Quote from: DaJMasta on September 25, 2024, 06:56:34 pmI do not know how to check Voltages for it. I do not have background on electronics, but i can learn very quickly. If you show me the way to check voltages, or point me to a source( video, page, blog etc) i will do it with great pleasure.If you are wondering, how i injected Voltage to the Card, while i do not have background on electronics, the answer is that i saw it somewhere, and i did it to check if there were a short , detecting warm points in somewhere on the Card.That is why i increased the Voltage to points more than 5 Volts (without knowing that i may destroy the ALTERA). I wanted to stress the Card...

author: kraka
author_rank: Contributor
timestamp: September 25, 2024, 09:57:08 pm
content: Quote from: fzabkar on September 25, 2024, 08:07:19 pmExcuse me, but what is VR1 and VR5 ? I can only inject Voltages (No more that 5 Volts- Now i learned my lesson...) off board.

author: fzabkar
author_rank: Super Contributor
timestamp: September 25, 2024, 10:06:32 pm
content: VR1, VR2, VR3, VR4, VR5 are 5 linear power supplies (+/- 5V, +/-8V, +3.3V).

author: kraka
author_rank: Contributor
timestamp: September 26, 2024, 10:02:40 am
content: Quote from: fzabkar on September 25, 2024, 10:06:32 pmI just measured the +8 and +5 Voltage Regulator's input and output.Inject : 12 VoltInput for both : 12 VoltOutput for +8 : ~8 Volt (7.90)Output for +5 : ~4 Volt (3.88)measurements on board-Card (for Regulators), off motherboard (for Card)I do not know how to inject -12 Volt...OK, I learned how to do it.Inject : -12 VoltInput for both : -12 VoltOutput for -8 : -8 VoltOutput for -5 : -5 VoltAs i can see from the datasheet of +5, the minimum output is 4.75 Volt and as you can see i got 3.88.It is a new one because i have, already, replaced the old one. Before replace it, again, is there else that maybe cause this wrong output ?

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 26, 2024, 11:44:39 am
content: I don't understand what you mean by injecting a voltage.But that +5V rail is not fine. To be precise, it looks like it sits above one diode above 3V3. From the keying of your PCI card, it seems like it is supposed to wotk in 3V3 and 5V PCI environments but that measurement looks like it behaves like a 5V driver on a 3V3 bus. Maybe. I don't remember enough about the PCI spec, especially not about how dual voltage cards are supposed to work to help.

author: kraka
author_rank: Contributor
timestamp: September 26, 2024, 12:20:59 pm
content: Quote from: Ice-Tea on September 26, 2024, 11:44:39 amI am sorry, but i have modified my previous post @fzabkar.Can you please re-read it ?When i am saying injecting Volts to the Card, i mean this :I have a Voltage Supply Station, in which i can variate Voltage output. This Device has two probes, one red one black. So, i connect the black one to the GND of the Card, and the red one to the Cards pin which is made to accept whatever Volts i want at this time. Then i switch the Volt selection switch to the Volt i want and as Voltages are created, then current flows in to the Card. At the same time i am measurement with the help of my multi-meter, the voltage comes in and out from the component i want to diagnose.

author: kraka
author_rank: Contributor
timestamp: September 26, 2024, 03:47:50 pm
content: Unfortunately, i think this is the end.I am very sad.Just a moment ago VT244 was de-soldered and removed, then the card was connected into the motherboard and booted into Windows. The ALTERA immediately got very hot, and by "hot" i mean i cannot hold my finger on it more than two seconds.I guess it is useless to replace the +5 Volt Regulator that instead of 5Volts, gives 3.88.Why cannot replace ALTERA ? I do not want to steal anybodies copyright. I just want to replace it, to buy it, for fixing the Card that i have bought.I just wanted to write music...

author: fenugrec
author_rank: Frequent Contributor
timestamp: September 26, 2024, 05:32:45 pm
content: Quote from: kraka on September 26, 2024, 12:20:59 pmWhere did you get the idea to do that ?? That is an excellent way to cause irreparable damage. There is rarely a need to supply power directly to a board, (especially 12V !?), on random pins, especially if you don't really know what you're doing. Until you know *exactly* why and how to do it, I suggest you don't try that again.If I understand correctly and you applied 12V to the 5V rail, you probably killed almost everything digital on that poor board. Sorry for the bad news.

author: fzabkar
author_rank: Super Contributor
timestamp: September 26, 2024, 08:50:11 pm
content: Quote from: fenugrec on September 26, 2024, 05:32:45 pmThe OP measured the correct voltages at the outputs of each VR, so that would imply that the correct voltages were applied to the inputs (+/-12V).The low output voltage from the 5V regulator could be due to overloading by the Altera PLD. It would be interesting to see where the +5V rail sits when it is disconnected from its loads.

author: kraka
author_rank: Contributor
timestamp: September 26, 2024, 09:48:38 pm
content: Quote from: fenugrec on September 26, 2024, 05:32:45 pmThanks for your sympathy.About applied 12V, it is not exactly what i said. What i described in my previous post about "what i mean about injecting...." was to describe how i diagnose the input and output Voltages to the four Voltage Regulators that exists on my Card, answering @fzabkar, who wondering about the output voltages at VR1 - VR5. This made with no mistakes. By the way the only strange result was the +5 output that was 3.88Volt instead 4.8 - 5.2.But... as i described in my first post, initially and after 1 and more year made everything i could to make this Card give me a little sound, i decide, because i had (or i could not do) nothing more to do, to give 12 volts to the card, to see if anything would warm up. But i made a mistake :Pin 2 on side A of the card is responsible for accepting 12Volts and this pin is the second closest to the backplate. I accidentally connected the supply to the 2nd pin on side A, but counting from the farthest, to backplate side, where there was pin 57, which has the AD label in green color and description: "Address / data bus (bottom half)" and "Signal I / O. Maybe driven by starter or target, depending on the function".I, still, don't know what that pin is. Anybody knows?

author: kraka
author_rank: Contributor
timestamp: September 26, 2024, 09:57:35 pm
content: Quote from: fzabkar on September 26, 2024, 08:50:11 pmSorry, but i do not get it. What do you mean by : "where the +5V rail sits when it is disconnected from its loads."Can you explain with details so for me to understand and do something to see ?Do you mean to de-solder the +5V Regulator ?

author: fzabkar
author_rank: Super Contributor
timestamp: September 26, 2024, 10:26:53 pm
content: Quote from: kraka on September 26, 2024, 09:57:35 pmI mean for you to desolder the Vout pin of the 5V regulator and then measure it. If it sits at 5V, then the regulator is probably OK. If it is much higher than 5V, then a failure in the regulator (unlikely) could be the reason for the failure of the PLD.

author: kraka
author_rank: Contributor
timestamp: September 26, 2024, 10:55:31 pm
content: Quote from: fzabkar on September 26, 2024, 10:26:53 pmI wish with all my heart, the failure to be on the regulator. It is little hard to de-solder only one pin. It is the DPAK-3 DT SUFFIX CASE 369C. This legs are short and hard and difficult to bend. I can, completely, de-solder it to measure it, or it does not need to measure it. If the PLD will not get hot, when +5 is out of the Card, then...What is your opinion ?

author: fzabkar
author_rank: Super Contributor
timestamp: September 26, 2024, 11:15:13 pm
content: The PLD is obviously bad. I'm just curious about the regulator.

author: kraka
author_rank: Contributor
timestamp: September 27, 2024, 01:04:10 pm
content: Quote from: fzabkar on September 26, 2024, 11:15:13 pm+5 de-soldered from the Card.It gives 3.78V output, when injected 12V in input.To give 5V, must inject 15VALTERA, continuous warming up, in the absence of the regulator.

author: fzabkar
author_rank: Super Contributor
timestamp: September 27, 2024, 11:01:17 pm
content: It looks like there is something wrong with the 5V regulator. Is it getting hot?The Altera device must be getting power from somewhere else. I think you need to investigate the power pins of the ICs in order to determine how they are powered.

author: kraka
author_rank: Contributor
timestamp: September 29, 2024, 12:03:25 am
content: Quote from: fzabkar on September 27, 2024, 11:01:17 pmNo, it is not getting hot at all. Now it is off the Card. I have de-soldered it and left it on the side.For the investigation : I can do this. Do you mean the pins of ALTERA ? And when you say: "how they are powered", do you mean to search-trace the buseson the board-Card? And by following these buses, find the components to which they (the pins of ALTERA) can be connected, and give power to the ALTERA?

author: fzabkar
author_rank: Super Contributor
timestamp: September 29, 2024, 08:08:28 pm
content: I don't think this PCB can be repaired. All you're doing now is a post mortem examination.

author: kraka
author_rank: Contributor
timestamp: September 30, 2024, 01:13:45 pm
content: I refuse to accept that this PCB is dead. Ιt is just sleeping...

author: kraka
author_rank: Contributor
timestamp: November 09, 2024, 02:54:27 pm
content: ΟΚAs I said in my last reply, in response to fzabkar, the card did not die, but just slept.The card was wake up or resurrected. Call it whatever you want.The suspicions I had that the PLD had, long before I experimented with the card, been damaged by a faulty PSU, probably turn out to be true.It was repaired by "transplanting" from a donor card. Α forum member gave me this idea and he really helped. It was very difficult to find such a similar card. I found it in an old shop and although it was sold only for spare parts, gave me its PLD and replacing with it the short-circuited PLD of my own original card I made this card work again.Thanks everybody for help.

author: wraper
author_rank: Unknown
timestamp: November 09, 2024, 03:09:46 pm
content: I suggest replacing vreg before trying something else. Lack of one supply voltage may cause funny business and heating of parts powered from somewhere else.