ONLY DO THIS IF YOU ARE A COMPETENT ENGINEER otherwise you could die. I don't want know if you do kill yourself, you have been warned.
It all started with distorted sound, no other symptoms. I unplugged and moved the unit to my bench but when I powered it up there was a sound like frying chips along with a horrible smell of burning
The main switching chip (the one on the big heatsink) had exploded, a resistor or two had disappeared along with some PCB track.
Why did JVC use 1mm square SMD resistors in a PSU when they didn't exactly need to save space?
Anyway, I ordered the following from RS
127925 100uF 400v
144223 680R 0.25W
2942849 R27 2.5W
2244218 1000uF 16v
2244331 22uF 50v
3150827 27uF 50v
1918132 220uF 10v
4490996 1500uF 16v
5261569 680uF 25v
2671727 47R 0.5W fusible
144318 3K9 0.125W
151798 100R 2.5W
148253 5K1 0.25W
And the STR-G6653 from Grandata
Then set about replacing lots of components. I used 1500uF to replace the 1200uF's, the only tricky parts were as follows:
5K1 which replaced R5304 and 5305, remove both SMD's and the wire link
and solder the lead of the 5K1 in to replace the link and the other end of this resistor to pin 1 of IC5301 on the track side.
R5107 I had to solder one end to pin 5 of IC5101 and the other end to R5108
I had to use a short length of wire from R5108 to pin 2 of IC5101
R5106 had changed value to around 182K, I drilled two holes to allow me to solder this resistor in place of the SMD
I had to drill new holes for C5003's replacement
C5103 had dropped it's value to about 10uF
I checked the opto using a couple of 270R resistors, two LED's and a 5v supply on a breadboard, it was ok. I checked all the diodes, transistors, rectifier, resistors.
When all this was done I was surprised to find the PSU worked and the sound fault had gone
The two faults are un-related. The sound fault appears to be fixed by following a JVC service bulletin which involves soldering three resistors onto the digital board, but this is very tricky due to the size of the surface mount resistors that the three resistors need to be attached to.
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- Joined: Mon Jan 24, 2005 11:38 am
- Location: Pendle Witch Country, Lancs
Well done that man for perseverence.
Imagine what its like for us engineers that have had to do the 3 resistor mod to every one of every model in the range and had to rebuild the psu as above on several machines when they blow up.
No wonder JVC has ceased selling all but 1 of these DVD recorders. (which they don't actually make ... shhh)
I couldn't have fixed the sound fault without your help!
So thanks for that. I didn't think it was possible to earn a living doing TV/Video repairs these days!
If I added up the time I spent and multiplied by the minimum wage I think the bill would be more than the cost of the DVD recorder!
Electronics is a hobby so I just did it for the challenge...
this is a long shot, as this is an old thread/machine I know, but I have one of these brilliant HDD DVD recorders and it's been a joy to own, until I accidentally blew it up!
I'm hoping someone can offer some advice on how to go about repairing it. I have some experience working with electronics as a technician and hobbyist but I'm no engineer! I have nothing to lose though so willing to give it a try..
First the problem:
It happened when I accidentally shorted the SCART connector on the back..there was a big spark and a popping sound and the machine lost power. I opened it up and noticed a glass 2A quick blow fuse had gone on the PSU so replaced it and powered up..it blew instantly again. So did 2 more.
On examining the PSU board closer I noticed a big scorch mark near a diode (D5106) so I'm wonder if that is burnt out and needs replacing..that might explain why the circuit is shorting out the fuse.. Problem is I have no clue which diode to use and do not want to remove the PSU board if I can help it which appears to be clipped down by those annoying white expanding plastic plug things... so my plan is to solder a new diode across the top of the old one, or just clip out and leave the legs in and solder the new one onto the legs.
I looked up the diode in question on the board which appears to be a
ERA 18-02 fast recovery diode 200/400V / 0.8A.
Does my repair approach sound feasible? Maybe it's a more serious problem?