Hello everybody!
I am a newbie and eager to learn, please don't laugh me 😀 for my stupid question.
I have a old denon avp-a1hd preamplifier, recently the sound will be dropped after playing 15 to 20 minutes. I replaced the original small fan with a bigger one, that makes the playing time longer, about 1 to 2 hours depending on room temperature. The problem is only happened when the input source is via digital such as coaxial cable, playing via USB etc. For example, if I connect my cd player via coaxial cable, the problem happens, however if I connect via xlr cable, it works fine.
It has too many pcbs inside the amplifier, I am hesitated to unmounting those board without any clue.
My question is what is the most likely reason for the failure?
Could anyone please help me to work a way to fix the problem? Thank you very much!
Felix
I am a newbie and eager to learn, please don't laugh me 😀 for my stupid question.
I have a old denon avp-a1hd preamplifier, recently the sound will be dropped after playing 15 to 20 minutes. I replaced the original small fan with a bigger one, that makes the playing time longer, about 1 to 2 hours depending on room temperature. The problem is only happened when the input source is via digital such as coaxial cable, playing via USB etc. For example, if I connect my cd player via coaxial cable, the problem happens, however if I connect via xlr cable, it works fine.
It has too many pcbs inside the amplifier, I am hesitated to unmounting those board without any clue.
My question is what is the most likely reason for the failure?
Could anyone please help me to work a way to fix the problem? Thank you very much!
Felix
This is a massively complex unit and I think you have to be realistic in what is possible at a diy level.
Your main clue is that extra cooling seems to let it work for longer and crucially that it only affects digital inputs.
Faced with that I would begin by looking at the digital signal processing and possible trying sparing use of freezer spray to cool any chips directly involved in the digital signal decoding path. Freezing any good chip should have no effect and so its a good way to look for thermally defective parts.
Along with that you must always (first rule of faultfinding) check all supplies to the relevant areas under both working and fault conditions.
As I say though, you have to be realistic in this and working on a unit like this is a daunting prospect for even an experienced technician.
Your main clue is that extra cooling seems to let it work for longer and crucially that it only affects digital inputs.
Faced with that I would begin by looking at the digital signal processing and possible trying sparing use of freezer spray to cool any chips directly involved in the digital signal decoding path. Freezing any good chip should have no effect and so its a good way to look for thermally defective parts.
Along with that you must always (first rule of faultfinding) check all supplies to the relevant areas under both working and fault conditions.
As I say though, you have to be realistic in this and working on a unit like this is a daunting prospect for even an experienced technician.
Pres and integrateds out of this generation have nearly frequently failing digital boards because of overheating. This results in bad solderballs under the BGAs or simply died processors. The first one is yours.
Try to give the board to an expert who is able to do some reflowing. Alternatively buy a new board. But that could be difficult and/or very expensive.
Try to give the board to an expert who is able to do some reflowing. Alternatively buy a new board. But that could be difficult and/or very expensive.
Thank you for all your suggestions, I totally understand it's very difficult to fix the problem by myself. However, I am thinking this is not just for repair something, it's also perfect learning circle for my circuit analysis ��
Oh no - let me guess: TI TMS320 series DSP, rev. A or B silicon? Those had problems with premature aging, causing problems all over the industry (e.g. Onkyo HDMI boards).
It can't hurt to be testing the responsible supply voltages (just to rule out bad solder joints on voltage regulators) and, if the DSP is one of the suspect ones, hitting the DSP with the heatgun for a bit - but obviously you should be somewhat experienced with this by this point.
In my opinion, ANY AV receiver that has that top row of "digital" jacks is prone to failures.
They were mass-produced boards made in china with issues.
Made "in a hurry" there to supply multiple manufacturers products all scrambling for "the latest" HDMI features.
In fact, my parts suppliers were all out of those type of boards due to the worldwide failures.
The problematic TI TMS320 series DSPs were fixed in revision D; last time I checked, one of these D830....xDxx chips for an Onkyo was about $25 a pop. Need to be able to solder a BGA, of course.
Thank all of you! I followed Mooly's instructions, finally found the problem chip! it's a cFeon en29lv160bb-70tip
E42698h 1124tsd
I don't know whether those E42698h 1124tsd numbers matters or not, I can find cFeon en29lv160bb-70tip with different numbers below.
E42698h 1124tsd
I don't know whether those E42698h 1124tsd numbers matters or not, I can find cFeon en29lv160bb-70tip with different numbers below.
Attachments
Oh well done 
I would say those numbers are not important and will be production codes (the 70TIP is the important bit as that will determine the unique configuration internally of the base chip... like a ROM mask).
That chip is do-able as a diy repair but if you've never done SMD work and re-work before then practice first on something else.
Working with SMD. How to do it without specialised tools.
I would say those numbers are not important and will be production codes (the 70TIP is the important bit as that will determine the unique configuration internally of the base chip... like a ROM mask).
That chip is do-able as a diy repair but if you've never done SMD work and re-work before then practice first on something else.
Working with SMD. How to do it without specialised tools.
Thank you! Yes, those numbers are lots numbers and production date.I have ordered several from China, will keep updating the thread once I have done. Thanks for all of you!
Did you ever resolve this issue?
Issues with sound levels on the AVP A1 can also be traced to failing caps on the digital audio board (the board directly underneath the hdmi board). Denon didn't do a very good job controlling the heat with the horizontally stacked boards and the temps can get very high - enough to cook those caps. The most common fix is to replace all the caps on that board. I think there are about 48-50 of them.
Issues with sound levels on the AVP A1 can also be traced to failing caps on the digital audio board (the board directly underneath the hdmi board). Denon didn't do a very good job controlling the heat with the horizontally stacked boards and the temps can get very high - enough to cook those caps. The most common fix is to replace all the caps on that board. I think there are about 48-50 of them.
I'm afraid not; The most important bit is 29LV160. That says it's a 16Mbit flash memory device. Any letters preceding it refer to the component's manufacturer. Yes, different manufacturers produce devices that should be compatible.
No, the 70TIP part is not important at all: It indicates the component's speed grade, in this case 70ns access time. It may be replaced with faster version, with a lower number.
Yes, but if it contains firmware, replacing it without copying the contents to the replacement component may not solve your problem.
A factory reset may get it reprogrammed, but chances are slim. If you can copy the contents, do so.
The Digital Audio PCB (1U-3818) contains 3 of these flash memory device, with reference designators IC302, IC403 and IC503. The service manual names them respectively DSP1 ROM ASSY,DSP2 ROM ASSY and DSP3 ROM ASSY. Their original part number is S29AL016D90TFI020, a component manufactured by Spansion.
Its over two years ago now but quickly skimming the post and what was said, and it seems he was referring to the 'numbers below' which look like production codes to me.
I stand by what I said at the time. Those numbers were E4269H and 1124TSD which are in the picture.
Those probably are.
I was searching the web for an intermittent digital audio problem with my Denon AVC-A1HD. Not the fancy AVP, but close enough. I stumbled upon this topic and was intrigued about the possibility of my amp suffering from the same problem.
I bought a second amp, but it's suffering from a thermal problem with digital audio playback, so no board-swapping. Unfortunately, this post is my only lead.
Here I have to rectify; Digital Audio PCB (1U-3818) does contains 3 of these flash memory devices, but these are most likely not the ones the topic starter refers to. He most likely refers to reference designators U1003, U2002 and U3002, which are located on the DSP Unit (U8-310098), which is a piggy-back board on the Digital Audio Unit (1U-3818). Unfortunately, there's no mention of it in the Service manual. Perhaps I have an old manual and was it part of the 3D update.
@nzfelix: Did you even fix this problem? I know it's a long time ago, but this amps last a life time.
Hello,
I just came across this discussion. I hope to find some food for thought there, perhaps even solving the problem encountered with my avp a1hd. the problem with mine being that I have no sound when I use the digital section (coax, hdmi). I swapped with an operational card from another avp and thus confirmed that the problem comes from the digital audio card!! I replaced all the smd capacitors which were all either open or with a very high esr... Indeed it heats up a lot on these cards and therefore it reduces the life of these capacitors. Unfortunately for me replacing all abilities didn't change anything. If anyone has any avenues to explore, I'm all ears. I have some measuring equipment (oscilloscope, generator, etc.)
To read you Yroger.
I just came across this discussion. I hope to find some food for thought there, perhaps even solving the problem encountered with my avp a1hd. the problem with mine being that I have no sound when I use the digital section (coax, hdmi). I swapped with an operational card from another avp and thus confirmed that the problem comes from the digital audio card!! I replaced all the smd capacitors which were all either open or with a very high esr... Indeed it heats up a lot on these cards and therefore it reduces the life of these capacitors. Unfortunately for me replacing all abilities didn't change anything. If anyone has any avenues to explore, I'm all ears. I have some measuring equipment (oscilloscope, generator, etc.)
To read you Yroger.
I’m afraid there’s not much hope, Yroger. Failing digital audio boards are a common problem with this machine, and it’s integrated sibling, the AVC-A1HDA. I own two of the latter and the first one started to exhibit crackles on digital audio after it’s running for some time. I bought a second used unit to diagnose and possibly fix it, but it turned out to have a similar problem. Instead of crackles, digital audio cut out completely after playing for a while. In both machine’s the problem is definitely in the digital audio board.
I am very familiar with electronics engineering and repair and I have all the equipment, but I decided to bring in the first machine to an authorized repair shop, because of the test-jigs, extender board and firmware update tools required to work on it. I got a quote for 1500 Euro, a remarkably round number, and after a long think I decided to have it fixed. I’m not sure if that was a quote intended to make me give up, or that they still have a source for these boards, originally sold at $740 up to ±6 years ago. I’m guessing it’s the first, because it’s at the repair shop for 3 months now.
On my second machine, I measured all caps, because someone on the internet said the caps got bad due to overheating. This guy seemed to know his business. But there’s a lot of one-trick repair pony’s out there. Anyway, the caps on my second board seemed OK, both for capacity and ESR, as far as I could measure that in-circuit. I needed a little more heat than I was comfortable with to removed them, so I didn’t replace any.
I would love to upgrade to an AVP/POA combination, but since there’s no way of telling if and AVP is still good, and if it is, for how long, I’m reluctant of investing in the still hefty price they demand here in Europe.
I’m still curious about other failure modes of this board besides bad caps, but information is scarce. Best of luck!
I am very familiar with electronics engineering and repair and I have all the equipment, but I decided to bring in the first machine to an authorized repair shop, because of the test-jigs, extender board and firmware update tools required to work on it. I got a quote for 1500 Euro, a remarkably round number, and after a long think I decided to have it fixed. I’m not sure if that was a quote intended to make me give up, or that they still have a source for these boards, originally sold at $740 up to ±6 years ago. I’m guessing it’s the first, because it’s at the repair shop for 3 months now.
On my second machine, I measured all caps, because someone on the internet said the caps got bad due to overheating. This guy seemed to know his business. But there’s a lot of one-trick repair pony’s out there. Anyway, the caps on my second board seemed OK, both for capacity and ESR, as far as I could measure that in-circuit. I needed a little more heat than I was comfortable with to removed them, so I didn’t replace any.
I would love to upgrade to an AVP/POA combination, but since there’s no way of telling if and AVP is still good, and if it is, for how long, I’m reluctant of investing in the still hefty price they demand here in Europe.
I’m still curious about other failure modes of this board besides bad caps, but information is scarce. Best of luck!
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