Faulty ATX PSU in Dr. Dre Beatbox - any suggestions as to cause. (Not ATX)

[Mark Hennessy]

Look, let's please put the ATX thing to bed.

It is not an ATX power supply.

As I explained in post #7, an ATX power supply is for computers. I gave a link to the full ATX specification. At no point in the ATX PSU specification will you find +/-7V and ~50V.

This "Beats" power supply might share some aspects of an ATX PSU - although there is great variation in ATX PSU design, as there are many ways to build an ATX PSU that meets the ATX specification - but then so would many other switched-mode power supplies.

As for "PavoUk", that is not a manufacturer's website. That link takes you to the (very interesting) personal website of a gentleman called Pavel Ruzicka, and that specific page contains a schematic that he reverse-engineered from an ATX PSU that he repaired some 15 years ago. It has nothing to do with the PSU in question, even if it does have some similarities.

Thank you.

[Murphyv310]

Hi Mark.
I agree that it isn't an ATX PSU. I've yet to come across a dedicated audio unit that would use this type of supply unless it was home made.
I tend to get frustrated when advice is given and not heeded.

My reference to T2 was a general idea not a connection to the specific diagram, my point was if the manual isn't there well would you expect to get the transformer, perhaps I didn't make myself clear.

[Mark Hennessy]

Don't worry, Trev - I wasn't thinking about your posts when I wrote that

If the customer decides to go ahead - and he/she might not, of course - then I'll reverse-engineer the schematic and post it here for all to see - even if it proves to be BER. That will help people in future, and finally put some facts on this multi-thread, multi-forum saga.

[Murphyv310]

Excellent Mark
Your dedication is second to none.

Being quite honest I'd have thrown in the towel a long time ago. When you consider the hours spent on it, looking for help on two forums and no doubt other places is it really economic? I could have repaired plenty of other items rather than spending fruitless hours on an unknown, sound business in my mind.
Latterly I made up my mind that after the customer leaving the unit and paying a £20 non returnable deposit (sorted out the time wasters or those that wanted a repair for a fiver) I then did straightforward firstline checks, i'd enquire if a manual was available and of course spares. Gradually it got worse, even companies like Samsung and even B&O were getting more and more less helpful to even their own dealers.
If I thought I couldn't turn around a repair in under 14 days then I'd return it.... yes and keep the deposit, it took me time to dismantle the unit, enquire about service info and parts etc, also the running costs of the workshop, feed the family and pay the mortgage.

The other thing is that a lot of us older chaps that have worked for small retailers will not be properly trained, the many advances over the years will be pretty well foreign for many engineers, I was lucky before I went self employed having worked for multinationals and Sony too, the training was second to none.

My advice is stick to what you know or retire and enjoy your remaining life, i'd not like to be stuck in an windowless cellar fixing modern crap, enjoy life and get out of this God forsaken trade.

[Mark Hennessy]

Well said!

My workshop is also a windowless cellar, but I hope that by the time I reach my 70s I'll at least have somewhere with a window . I'm lucky that I get plenty of natural light when I'm at work, but when I have time off, I do start to go a bit mad down here after a few days. At least most of what I do in my workshop is for my own entertainment - if this was what I had to do every day to keep the roof over our heads, I'd be pretty depressed before long.

Still, we can only give advice from our perspective - much as we might worry about Old Sparky when we read about these sorts of jobs, it's ultimately his call. I suspect (and hope!) that he quite enjoys the challenge, but like you say, there must be better ways to keep body and mind active. Ask me again in 30 years time

Any word from your customer yet, OS?

[boater sam]

Its a very pleasant and well equipped cellar that Mark spends his time in.
I also think that if the manufacturers don't think its worthwhile making service info available, we should consider repairs to their modern nightmare goods not worthwhile either.
The problem is of course that most products now are an amalgam of sub assemblies from different makers.

[Nick]

PSUs are definitely a specialist art firm, especially SMPS units - almost no-one makes their own.

However, that doesn't mean that you can't repair some stuff - I've repaired several flat screen TVs, either replacing backlight LED strips (replacements easily available for most TVS) and re-capping SMOS units that drive them (common problem with Samsungs and some others).

The big question is "what constitutes economic repair? i.e. how much do we value our time at.

Like most here I suspect, we hate chucking stuff out - I may have a degree in EE and have designed avionics for fighter jets, but SWMBO has me fixing all the white goods in the house - two days on the dishwasher alone! She costed that repair at GBP 100 for the new pump and pressure switch off eBay, i.e. compared with the cost oi a new Miele unit, a complete bargain. I costed it as GBP 100 PLUS two extremely rare and valuable days of my Christmas break - nearly 20% of my holiday time.

Economic? Borderline. I only do repairs on stuff for close friends and family.

[boater sam]

We were agents for lots of domestic appliance manufacturers but only repaired if we had full access to spare parts and all information and if we were retailing too.
Italian makers were constantly asking us to do under guarantee repairs but had no parts for new models.

[Nick]

PSUs are definitely a specialist art form, especially SMPS units - almost no-one makes their own.

However, that doesn't mean that you can't repair some stuff - I've repaired several flat screen TVs, either replacing backlight LED strips (replacements easily available for most TVS) and re-capping SMPS modules that drive them (common problem with Samsungs and some others).

The big question is "what constitutes economic repair?" i.e. how much do we value our time at.

Like most here I suspect, we hate chucking stuff out - I may have a degree in EE and have designed avionics for fighter jets, but SWMBO has me fixing all the white goods in the house - two days on the dishwasher alone! She costed that repair at GBP 100 for the new pump and pressure switch off eBay, i.e. compared with the cost oi a new Miele unit, a complete bargain. I costed it as GBP 100 PLUS two extremely rare and valuable days of my Christmas break - nearly 20% of my holiday time.

Economic? Borderline. I only do repairs on stuff for close friends and family.

[Old Sparky]

Having spoken to the owner of the Beatbox earlier today and been told that they have decided not to proceed further with repairing the unit, and with other things to do, I have come to the decision not to spend any more time on it, at least for the immediate future. I may return to it if, and when, my workload is less than it is at present (I have 8 or 9 jobs in various stages of progress, some of which have been 'on the back burner' for some months.