Genius SW 5.1 DHT-510 - No sound?

[zynix]

Re: Genius SW 5.1 DHT-510 - No sound?

Please pardon my ignorance, but, given the results, should I redo the measurements (if some values perhaps seem wrong), check for some more burned elements after the mishap, or should I simply proceed to ordering two TDA7269A's and one TDA7360?

EDIT: I will certainly redo the measurements ASAP as the values for the main subwoofer IC should be different (now that it's burned, gah!), but I'm not touching IC2 so that I don't burn that one too .

EDIT 2: There is no free shipping TDA7360 on sale on eBay (nor CT1975 which was mentioned on a few places as a potential replacement for it) so ... any thoughts about ordering from AliExpress? Would I get a legit chip or a cheap piece of plastic barely mimicking the real thing?

[zynix]

Re: Genius SW 5.1 DHT-510 - No sound?

Okay, school's over. May it rest in peace ... for a while . I've just survived my first year at the university, but it's the same thing as elementary and high school were (a pile of tiresome education), so I refer to it as school nevertheless.

Back to the topic!
So, yeah, I was stupid enough to order a pack of 5 TDA7360s from AliExpress (got six of them), due to a stupid typo in posts #20 and #21 and general thought process mistake. I know, it's absolutely my fault. I got pissed off because that little multimeter probe slipped between pins and made the fixing process even more complicated, which resulted in me typing nonsense and buying unnecessary parts. Hope they are going to be useful someday for something else. Sorry for the confusing ramblings in aforementioned posts. Indeed, yes, it was the IC2, TDA7296, not TDA7360 (duh!) that got hurt in the measurement process. TDA7360 is still fine. At least so far. I've ordered a 5 pieces lot of TDA7269As too (also from AliExpress), so it's not completely a miss, at least I hope so ... unless if they're fakes. As soon as the TDA7269As arrived, I fired on the Genius once again to make sure front left/right and rear left/right channels (i.e. ICs 3 and 4) are not outputting sound. They were still mute, and the subwoofer hummed in the rhythm of music, but waaaaay quieter than before I messed up stuff ... so hopefully, not everything in the IC2 stage is burnt. Then, as wise as I am (irony!), I jumped right on to desoldering IC3. Obviously, I forgot to re-measure the voltages ... . So, I'd kindly ask you, the unwilling (and probably way more experienced) reader, to resolve the following doubts of mine.

More measurements?
As I've unnecessarily rushed to desolder everything (um, just IC3, but this way it seems more dramatic:P), could I do further measurements regardless? Will something be burnt if I turn the Genius on in this state (lack of IC3)? Is there any use of the values in post #20, could something be extrapolated (if not concluded) from the values there? Correct me if I'm wrong, but as far as I can see, for TDA7269As I should have measured the +Vs > GND voltage too to see in which MUTE/ST-BY state are they. TDA7296 datasheet, in the meantime, completely baffles me.

Counterfeit chips?
After ordering and receiving TDA7269As, TDA7360s and one TDA7296 from eBay, I found out that parts bought from Chinese sellers on eBay and, even more often, AliExpress, tend to be relabeled lower power parts from the same manufacturer, or a mostly similar (sometimes even pin-compatible) part from another manufacturer. As always, there is a lot of information on the Internet, varying from X-ray scanning to wiping the chip with acetone or alcohol and inspecting with a microscope. I wiped them with acetone and alcohol and nothing happened, just in case anyone wondered. I've attached a few images of the TDA chips I received to eventually shed some light on my dilemma, and a photo of the original TDA7269A for some, eventual, reference.

Any help is greatly appreciated!

P.S. I just found this thread on some Russian forum, someone is, as far as I can tell from the label on the PCB, encountering the same problem with the same device. He took some nice pictures too. Maybe useful?

P.P.S. Uploading 8MP images cropped to 3000 pixels of width/height failed although image size and dimensions were okay. Uploaded to Imgur instead, hope you guys don't mind.

[zynix]

Re: Genius SW 5.1 DHT-510 - No sound?

Quick update. I've replaced the TDA7269A IC3 with the AliExpress part, but no luck. Solder joints are good, approximately zero resistance from chip pin tips to the next directly connected point on the PCB. Will dig deeper and research above questions as soon as I find some time.

[gsinko]

Re: Genius SW 5.1 DHT-510 - No sound?

Hello, Seems i have the same issue with mine subwoofer and i am planning to fix it. Were you lucky with yours have you fixed it?