hi I have Marantz AVR SR6005 No audio and no video output. input non sensing nou sound in fm and usb in pure direct mode. all voltages are correct in hdmi board 5v, 3.3v, 1.2v, 1.5v
Hi, Interesting stuff you do... I am a bit like this but.. I have a 24 year old Denon D-UTF88 system in mint condition, but I think I have inadvertently damaged the system inter-connect function. This probably whilst trying to replug it to make all the units respond to the handset.. The cables are 3.5mm stereo-like connectors which allow the handset, via the main amp, to control the tuner, CD and cassette. This no longer works, it did!, so suspect it may be blown transistors on the outputs. I have the full Circuit diagrams for each part, and there appear to be a NPN/PNP pair, plus one, on the outputs.. Do you have any knowledge of this as to what the fault may be. I am tempted to try a repair but dont want to proceed without some idea of what it is.. In all other ways the system is working fine, well, aster replacing both the CD and cassette rubber drive belts which had 'relaxed' too much! Cheers Paddy
@@Eclectronicschannel ah that's a shame.. made it through all the parts and am really hoping it's similarly 'simple' as some bias adjustment and added resistors. I'm guessing you never ended up finding schematics? web-archive's save of Dare's old website was sadly no help
can it be a fuse if over driven with that familiar smell and protection mode constant .I ran it with one channel open circuit AVR2000 denon.? What a loose banana l am , but you should hear my mixing ear. Blows you away .
Denon: Bridge rectifiers in parallel???? That's a bad design decision. Even with matched pairing there will be overloading of the weakest diode in this construction.
hi, i know its an old vid but maybe wortha shot.... does yours work with only 3 tubes in? I have a very similar prebuilt one from china. Tubes sold separately. But stupidly i bought only 3 tubes as i mistook my in-15b for an in-12. Got another coming but thought id tests it in the meantime but the tubes dont come on, only the LEDs
My Denon 3806 will not turn on or anything at all. Idiots don't know how to box items when they ship! 3806 is a nice unit, I'd spend the money to have it fixed, Denon new stuff is garbage build quality.
I have a mcgreggor amp that uses 3pairs but 140v 2sk134 and 2sj49. Its rated at 300into 4ohm and 200into 8ohm. What would tha max rail voltage would you reccomend? It sags to 53.4v at full load 4ohms from the unloaded 65v
I made a fm receiver when I was 14 and never could get it to work, the idea of getting back to those projects feels good now that we have a lot more knowledge. I have recently dug into amplifier design and now I am looking at videos like yours so I can adjust a Quad 303 amp that I have had for 20 years.
I still have one working [stereo unit similar to this], that I built in the same casing, but mounted the two modules at the back - with larger heatsinks being able to dissipate heat externally.... I went the extra-mile and supplied each amp with its own separate supply - two mono blocks, in effect. This increases the bass response and punch, and to be honest puts to shame some of today's amplifiers that claim to be '500 Watts' or more 😀
Hmm don’t like the arrogance towards the manufacturer if this device … makes me a bit ashamed to be associated with the electronics trade myself … but each to their own
Thanks for your very interesting and useful video! I made the capacitor replacement and also that “hdmi out off” setting, it works perfectly now, after cracks and pops every time I turned it on! Dan, sound engineer
Hello sir, I have model 1804... very good build, but when i touch ac rails from rectifiers it shows open.. also when I touch middle ground with ac rails it shows open only one shows some resistance... I disconected receiver cable from power and measure it, are my rectifiers gone open??
Hello, thought I would take a chance here. I have the Denon AVR-587 very similar on the inside. in my case doesn't even turn on, I don't hear any relays clicking and then I tried to connect a table lamp to the back panel power AC outlet, so nothing so power isn't flowing even to the near by AC outlet on the back. So clearly not getting passed the very first few inches of circuit from the AC cord. I checked for broken solder joints and even the first relay, the two fuses. So frustrated.
OMG why would you not take that outside and blow all the crap out of it? I was given this same amp from a friend and just lately it blew what is supposed to be a 6.3 amp fuse that was a 7 amp 240 volt...
Maplin Electronics eventually sold upgraded Mosfet transistors with a higher voltage rating topping out at 140v to 160v breakdown voltage. Also sold a bridging module with a speaker protection and a claimed 400W output. Projects by them peaked in the late 1980's to early 1990's pre MPS era and the rise of Velleman and Quasar Electronics.
MPS was just an (ultimately doomed) attempt at a trade offering to go up against RS & Farnell. It was the terms of the investment Maplin took in the early 90's that was the beginning of the end. We'd previously had a lot of freedom to manage our own stock levels - but the edict came down that we were no-longer allowed to - that the value of inventory had to be reduced. The stock levels of many items no-longer made sense. We lost regular customers who understandably didn't react well to being told that if they wanted to buy speakers in pairs, or cabinet feet in fours, and so on, they'd have to pre-order them in or get them mail-order.
I have a pair of these, I'm using on in a guitar amp project. They are great little amps, the MOSFETS are becoming very expensive now if you can even find them. Have you ever attempted to bridge them? Might be an interesting experiment.
15:00 There are diodes parallel to mosfets 1 and 2, oriented up or pointing up (or whatever the term used). To transfer charge from V1 to V2 (ie, V1 > V2) MOS1 is turned on, it draws current away from V1 and into the inductor and into V2. Then MOS1 is turned off, the voltage at Vb drops to a low point such that the diode across mos2 will complete the circuit and charge V2. Buck charging. To transfer charge from V2 to V1 (ie V2 > V1) Mos2 is turned on. It draws current away from V2 and into the inductor and into V1. Then Mos2 is turned off, the voltage at Vb spikes up to a high point such that the diode across mos1 will complete the circuit and charge V1. Boost Charging. Rinse repeat using PWM to regulate the amp. The problem with this balancing is: It transfers charges between adjacent cells; it cannot transfer cells from C1 into C3 directly. And if you have 20 cells, you will have to ripple the charge across all cells. There is another inductor balancer using Transformer, which I believe is more superior than this Buck/Boost as it can balance on multiple cells and into multiple cells.
Is this amp design based off the old Hitachi L MOSFET design? I found schematics of the Hitachi design. I've contemplated building that amp since I have the l mosfets.
@Eclectronics greetings from Sweden! Your video is the closest I have come to understa d what is wrong with my Denon AVR-1905. It worked in the morning, but after a faulty toaster caused the Residual Current Circuit Breaker to cut the power at lunchtime, the receiver din't work in the evening - I guess these to events could be linked. The unit does not start up at all. No lights/display, no sound and no startup-buzz. Totally dead - but the fuse is ok! Any ideas how to go forward? Or is it fried? Thanks for a great channel, I've learned a lot! 👍
A couple issues... Cells have very low internal resistance. You cannot simulate them with resistor and a cap in parallel. The other one is that a power supply cannot sink current and I have plown up many big ones. Then I learned to use a diode in series. The I used anther diode to dump power to simulate the sink current. Since you sounded very enthusiastic and experienced, can you please tell me if you can do the same thing using a processor and Analog to digital converters?
Nice video. I have a SR6008 with a problem in the amplifier section. Do you have a service manual? I am willing to pay you for a copy. Thanks in advance,
I also always wondered why some designs put multiple MOVs in parallel. All I can't think of is to have a buckup - if the 1st one to conduct completely fails. The other day I installed a lightning protector between our electric fence and the energizer - it also has got about 12 in parallel, and of different sizes 🤷♂️
You could add a 1 ohm 5 Watt resistor from your transformer center tap to your ground ,it will limit the inrush current when the power supply capacitor are charging on turn-on.It will not affect power output and protect the bridge rectifier forever. Bye. Lucien.
