An expert who has achieved level 2 by getting 100 points
An expert that got 5 achievements.
An expert who has answered 200 questions.
An expert whose answer got voted for 20 times.
Re: Same Problem, diodes fell out of bridge rectifier...
Pulling to many amps,diodes could not handle amps so they failed.unit should have kicked its breaker before the diodes burned out.most units have their own breaker to protect the system.I would replace the control board first see how unit reacts,probly fine,if not the you go to next step.
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need. goodluck!
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Defect can be a switch (contacts / soldering or wrapps) ,or a fuse caused by a shorted rectifier bridge component or 1 diode in the bridge of 4 pcs , a shorted voltage regulator or shorted power mosnfet in the power supply. caused by a bad capacitor or soldering. DVD Home Theater Sound System
You smoked off the regulator , a transformer is for AC voltage change like say a step up or step down and the trxfmer just shot AC voltage to where DC should have been. The bridge rectifier is what changes the AC to DC not a transformer . If you have soldering skills you can replace it on the board , it could be you just cooked off a diode (1 of 4 to make bridge) . Hope this helps
If it's not the main board that's causing the fuse to blow then you have a short circuit somewhere in the power supply. Check things like the electrolytic capacitors. The ones that look like little cans. They should all have flat tops. If any are bulging out at the top they will need replacing. Also check the bridge rectifier which is a black component usually standing up on the board with four legs. If there is no bridge rectifier there will be 4 rectifier diodes together. They are black cylindrical items with a sliver band on one end and a lead out of each end. They are usually located near to where the mains lead enters the power board. Other things to check are power transistors, they are usually 3 legged, (sometimes 2 legs if they are used as a diode) black items with their case fixed to a heat sink (aluminium block.)
try adding .01mfd disc capacitors across bridge rectifiers diodes(all the 4 diodes),If the devise is old try replacing filter capacitors.and isolate transformer secondary leads if they are very near recifier board.
The most probable cause is a blown fuse on the circuit board. It is a cylindrical glass component with two chrome colored ends, located near the AC cord wires soldered to the circuit board. It can be checked with a volt-ohm meter, it should read minimal, close to zero ohms, across the ends. This fuse is soldered to the circuit board, mine is a 2A fast blow fuse with one lead attached to each end. If the fuse is OK or a replacement does not fix the problem, the bridge rectifier is probably bad as mine was. I rigged up 4 power diodes rated at 120 Volts AC and 2 Amps current as a replacement.
sounds like a bridge rectifier diode has shorted replace the bridge or make your own use 4 1000 piv diodes. can be purchased at radio shack. be sure to connect the diodes annode to cathode when making the bridge. also when a component shorts it generally opens the next component in series.in youre case i would definatley check the filter caps.sometimes if overloaded they will actually be swelled otherwise you will have to take them out of the circuit and read them with a cap checker on a quality multimeter. if bad be sure to mind polarity when replacing! electrolytic caps have a positive and neg. leg the board will be marked
To fix the problem, you need to disassemble the power supply, replace
the burnt out fuse, & also check the bridge rectifier section for
burnt out rectifying diodes (these usually get burnt out if the high
current gets the chance to leak past the fuse, which could sometimes
happen). If you find burnt out rectifying diodes, you will need to
replace them as well, as they could burn out the fuse again when you
try to use the power supply while they are still there.
there is a diode on the power line that blocks the dc to ground. follow pwr wires down to board. and the first diode on the + pwr is it. this is on all radios. and not just cbs. just put a new diode on the back side of the pwr plug. were the wires solder onto. but even better what we do @ our shop 254.718.4042 is use or make bridge rectifier install inline. and you will never have that problem either direction you plug it in. will work. no more worries about polarity.
Most likely what got burnt is the bridge rectifier in the power supply section of the electronic circuit. This usually takes the shape of either a single 4-legged IC, or a group of 4 rectifying diodes connected in a bridge configuration. If you disassemble the unit to which the power cord is attached & trace the circuit starting from the terminals of the power chord, you can easily identify it. You will need to replace the 4-legged IC or the 4 rectifying diodes. You will also need to replace the fuse, since it is usually likely that it gets burnt if the unit is attached to 220V instead of 110V.