diyAudio (
-   Car Audio (
-   -   Help/Schematic for Soundstream PCA1500D (

cheqmate5000 28th June 2007 03:27 PM

Help/Schematic for Soundstream PCA1500D
Last night after work, I was setting my gains with an oscilloscope and for some unknown reason the 10x probe introduced about 1/4 ohm resistance between the output rails of my Soundstream PCA1500D car amplifier.

All four fuses blew. I replaced the fuses and the amp let the magic smoke out. I opened the amp and believe I blew two transistors and maybe a few passive components around the transistors.

I really need some help. Does anyone have a schematic for the Soundstream PCA1500D? Or maybe a schematic of one of the other amplifiers in this family? I plan to contact Soundstream tech support but am not expecting to get the schematic from them.

The components that I need to replace don't seem to have any markings on them to identify them.

If you need pictures to identify what components I need to replace, please let me know.

I really appreciate any help that you can give me.


1moreamp 28th June 2007 11:50 PM

Post or e-mail some close well focused pics, I'll try to get you started :)

audiobahnkid592 29th June 2007 05:39 AM

email sound steam I just did tuesday and they emaild my schematics to me

1moreamp 29th June 2007 08:27 AM

Please share it with me, I only have their older stuff. my e-mail works, I get enough spam from this site to fill a bucket with everyday.

many thanks in advance:)

cheqmate5000 29th June 2007 02:52 PM

Thank you all for your quick replies. I have emailed Soundstream and will let you know if I hear anything back from them.

I will get pictures of the amplifier this weekend and will post them.

Thanks again.

audiobahnkid592 29th June 2007 03:44 PM

It took them two days to get mine so be patient with them

cheqmate5000 24th July 2007 03:05 PM

I apologize for the late reply. I got married and was on my honeymoon for a week.

I now have the amplifier disassembled and I am starting to identify the parts that need to be replaced. It looks like I blew a couple power mosfets. I am having a hard time finding part numbers for each of the fets, but one of the fets near the blown one is a IRFZ46N. I will be uploading pictures of the board tonight after work for help identifying the blown parts.

It doesn't look like Soundstream is going to do anything for me. I have not gotten a response in over two weeks. I will try again but do not expect anything from them at this point.

cheqmate5000 25th July 2007 04:16 AM

Here are some images of the amplifier.

The first image is of the entire amplifier:

The next image is zoomed into the area where the FET blew:

The FET on the right is the one that blew. The next one to the left was cracked when I was removing the heatsink clip. The next one to the left (Q316) has been identified in an earlier post. I would like to replace all of the FETs/transistors all the way around the board.

Some of the TO-220 (I believe this is correct) packaged components have markings on them so I am starting to identify each one. I would appreciate if someone could identify each component or each bank of components so that I can verify that the correct components are purhased. Based on the part that blew, do you think anything else is damaged on the board? There is no visible damage to any other section of the board. I have started to clean the affected area with alcohol, but am not done at this point.

Please don't hesitate to give any suggestions or comments.

If you need any additional pictures please let me know and I can upload them.

Thank you for you help.

Perry Babin 25th July 2007 10:06 AM

This is a very sad day for me. Soundstream is using the same manufacturer as power acoustic. :(

Move all of the output FETs from side to side (gently) while watching the point where the leg goes into the body of the transistor. IF the leg doesn't move with the body of the transistor, it's broken internally. If the broken leg is the first leg, it can cause the amp to fail as yours did. Do this for the rectifiers also.

It appears that there is one transistor missing in the audio section (near the fan). There are generally 8 FETs there. If one is missing, at least 4 will have to be replaced so you should just replace all 8 of them.

Check the audio FETs for shorted transistors (very low resistance or a dead short between legs 2 and 3).

There are 2 driver transistors on the driver board that fail regularly. They generally have bad solder connections and are a slightly different color due to high operating temps. I think they're Q124 and Q125. They're MPSA42s.

It's possible that the power supply driver transistor survived but you should check them out of the circuit. The (KT)A1023s are the ones most likely to be damaged. I'm not sure of the circuit board designation but the numbers may be Q311, Q313, Q411, Q413.

Also check all of the power supply gate resistors (connected to pin 1 of the FETs).

If the fan hasn't yet failed, it likely will soon. If it doesn't turn freely, makes noise or doesn't spin when the amp powers up, it's defective. It's a 40x10mm fan and they are readily available. A defective fan will cause the amp to fail.

darw82 25th July 2007 10:21 AM

usually when FET fail, the gate drive buffer will also fail, check your gate drive transistor. If no gate drive buffer is used, then the PWM controller may be fail.

All times are GMT. The time now is 05:38 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 18.75%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio