DCi4|300 amp with flashing power LED.
Astronomer
Posts: 2
The manual says a flashing power LED is caused by the AC voltage out of tolerance. Not the case here. When the power supply goes bad in the DCi series amps the most common symptom is flashing power LED. Someone out there knows what to fix. Every DCi power supply on ebay has the same problem and is being sold for parts. The standby voltages are ok at; 15v, 8v, and 3.3v .
Pushing the power button I can see the "low" signal at the microcontroller pin but it wont power up. Grounding the "sleep" pin shuts off the power LED. I think the microcontroller is ok it just needs something! Both "sense" voltages appear to be ok straight off the AC line. A tech at Crown Audio said to hold down the power button then apply the ac power and continue to hold the power button in for 35 seconds. This should reset the microcontroller. No results.
No schematics or service manuals for the DCi series amps.
Any ideas?
Answers
Junked it. These amps have CPU controlled Switching Mode Power Supplies. There's no getting around the problem. Mine had a dead CPU chip.
Replaced the TL494C controller IC - did not fix this particular amp.
I have several DSi amps with versions of the above described issue. Is there any info about the SMPS out there, or, better yet, someone who has fixed these and can point to a common component failure? In my experience, this sort of problem is caused by the same item breaking (just like C196 fixing power up issues).
New to the forum, so, thanks in advance.
I have been working with psytech on this issue and have been able to repair two DSi amps with the flashing blue LED/Lo power error - I found one of the legs on the K2 relay desoldered on the underside of the motherboard. Resoldered the leg plus resoldered the other connections on both K1 and K2 - both amps are nominal.
I don't know why the leg comes undone, unfortunately. It presents as a power spike or fault due to normal power up.
(That's scytech!
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