diff --git a/content/posts/2017-09-11-denon-avr-4520-repair.md b/content/posts/2017-09-11-denon-avr-4520-repair.md index 30d2cc3..390b340 100644 --- a/content/posts/2017-09-11-denon-avr-4520-repair.md +++ b/content/posts/2017-09-11-denon-avr-4520-repair.md @@ -147,18 +147,26 @@ With that, I've narrowed the problem down to `Q808`, a `DHCT-C3` darlington tran ## Repair -As with almost every project, diagnosign the issue is much harder and time consuming than the -actual repair. The process is quite simple: +As with almost every project, diagnosing the issue is much more time consuming than the +actual repair. I ordered a _new old stock_ pair of transistors, this is a set of complimentary +`-A3` and `-C3` transitors including two insulating washers. - 1. Order a new pair DHCT-A3/C3 (they are sold in pairs) - 2. Replace both `Q808` and `Q809` with the new pair +![](/img/denon-avr2520-new-transistors.jpg) -Done. +Next it's a simple job to remove the old darlington transistors... -While I wait for the replacement parts to arrive, I figured I'd start using the amp already. -I have a 2.1 setup, bi-amping the front speakers. Luckily, the AVR allows me to select which -channel (Surround Back or Front Height) to use for this. I disconnected the `SBR` and `SBL` -amp board as I won't be using them and circumventing the DC power protection problem. +![](/img/denon-avr4520-new-and-old.jpg) + +and place the new ones. + +![](/img/denon-avr4520-new-transistors-soldered.jpg) + +Finally re-insert the amp board into the amp with some fresh heatsink compound. + +**Do not +forget to add the insulating washers to prevent them from shorting out via the heatsink!** + +![](/img/denon-avr4520-final-solution.jpg) ## Conclusion @@ -166,7 +174,11 @@ Replacing the DHCT-A3/C3 darlington transistor pair has resolved the power prote issues. I've been running the amp in my living room for a few days now and not seen any issue at all. -So, for the cost of a used entry-level AV receiver and € 20 in parts I've got +![](/img/denon-avr4520-final-setup.jpg) + +So, for the cost of a used entry-level AV receiver and about €15 in parts I've got an almost brand new Denon AVR-4520 top-of-the-line AV Receiver. :-) +_For those interested, I'm using the `SBR/SBL` channels to bi-amp my speakers._ + [hifiengine]: https://www.hifiengine.com/manual_library/denon/avr-4520.shtml \ No newline at end of file diff --git a/static/img/denon-avr2520-new-transistors.jpg b/static/img/denon-avr2520-new-transistors.jpg new file mode 100644 index 0000000..5cd236e Binary files /dev/null and b/static/img/denon-avr2520-new-transistors.jpg differ diff --git a/static/img/denon-avr4520-final-setup.jpg b/static/img/denon-avr4520-final-setup.jpg new file mode 100644 index 0000000..69505b0 Binary files /dev/null and b/static/img/denon-avr4520-final-setup.jpg differ diff --git a/static/img/denon-avr4520-final-solution.jpg b/static/img/denon-avr4520-final-solution.jpg new file mode 100644 index 0000000..c37880a Binary files /dev/null and b/static/img/denon-avr4520-final-solution.jpg differ diff --git a/static/img/denon-avr4520-new-and-old.jpg b/static/img/denon-avr4520-new-and-old.jpg new file mode 100644 index 0000000..6b6860d Binary files /dev/null and b/static/img/denon-avr4520-new-and-old.jpg differ diff --git a/static/img/denon-avr4520-new-transistors-soldered.jpg b/static/img/denon-avr4520-new-transistors-soldered.jpg new file mode 100644 index 0000000..cb87d70 Binary files /dev/null and b/static/img/denon-avr4520-new-transistors-soldered.jpg differ