- We started switchover on March 24th on Mendip. The BBC Mux has switched to 8k mode.

Initially I couldn't get it to find the Mux at all, but in the end it found it - but constant audio and video glitches. All other channels are good.

Aerial is good (tested on another box)
I've tried attenuators
I've tried tuning manually

Presumably the rest of the channels will go the same way on the main switchover next week.

Is this 'box in the bin' time ? - I shame because I really like it.

Could they fix it with an OAD?.

My switchover was last December, and I found the same symptoms. There is much on here about how others have got on so I won't repeat it.

Suffice to say that I have two DHD4000 boxes, both of which suffered picture and sound breakup after digital switchover. They are both working perfectly now after issues with the power supply were sorted out.

Perhaps the new transmission format requires a more stable power supply, and has highlighted limitations in the power supply which might not have been obvious on the old transmission format?

Advice once again is to have a look at your power supply.

I have my own DHD-4000 working now having had the same problems as you when Mendip switched over. The PSU can't cope with 8k mode and a full size hard disk at the same time. The only permanent solution I've found is to replace the disk with a laptop 2.5" one, using a large to small IDE adaptor to connect it. These smaller drives ignore the 12V supply and use less on the 5V, this frees the PSU to cope with 8k mode. Mine's been perfect since doing this.
Last edited by tghewett : 27-04-2010 at 14:18

Having struggled myself I can confirm that the most effective solution for me was fitting a 2.5 inch laptop drive.
I fitted a new Western Digital 160Gb ATA drive using a 3.5 to 2.5 inch adaptor as recommended by tghewett and the machine is now working perfectly.
The black screen fault when changing to an 8k mux for the first time still occurs, but I can live with that.

I've read people elsewhere have had issues with 2.5 inch SATA drives and IDE to SATA convertors, so I spent a couple more pounds and went with the older technology without subsequent issue.

Hope this helps someone else who might otherwise bin their DHD4000.

Have you tried replacing the PSU capacitors that are known to fail in this model? A £15 kit has to be cheaper than a Hard Drive.

I have two DHD4000s. One had the capacitors fail Summer last year so I duly replaced them.
Both boxes had problems after switchover however so the capacitors alone were not a solution for me.

We have been running with one box on a 2.5 inch drive and the other on the original 40Gb drive for a few days. The 2.5 inch drive is working perfectly whilst the 40Gb drive unit does have the occasional minor bit of interference.
I'm thinking of moving the second box over to a 160Gb 2.5 inch drive as a stop gap until Freesat HD PVRs start appearing at sensible prices.

Very interested in these comments that replacement of the hard drive is a cure. I have two 4000's which are now in the loft. Might get them out again. Martin, I tried a PSU capacitor replacement and it didn't work for me. I even in desperation tried a replacement of all the capacitors on the main board. It still worked, which surprised me , but the fault was still there. (picture/ sound breakup).

I've had a couple of private messages with tghewett, and as a result I have copied his advice. I bought a Samsung Notebook Hard Disk 2.5 Inch Drive 160GB IDE from R U SMART TRADING LIMITED through Amazon for £42.50, and a 3.5" IDE - 2.5" IDE Laptop HDD Adapter Cable from CDL Micro again through Amazon for £3.99. All you have to do is remove the 3.5" drive from its plastic caddy, and disconnect the ribbon cable and the power cable. Next connect the adapter cable to the main board, and connect the power supply cable into the adaptor cable. I was unsure which way to connect the adaptor cable to the new 2.5 HDD, as this one is capable of being connected either way round. Obviously if you get it wrong you are likely to fry the HDD. Tg advised me to have the power connection at the opposite end from the four jumper pins on the HDD, or to put it another way, the power goes into the HDD at the far point from the front of the Thomson, if you have mounted the HDD with its label uppermost. If this is not clear send me a message and I'll email a photo. Once connected I fixed the new 2.5 HDD into the caddy using sticky tabs.

I have just tried it out and the reception is now greatly improved, and I would describe it as 95% of perfect. I still get the very occasional freeze or blockiness, and sound glitch, but not enough to be a problem. The reception had become totally unwatchable, but is now fine, if not perfect.

I'm going to try it out for a week, to see how good the recordings are on different channels, and then hopefully upgrade my other Tommy the same way. This way I can postpone buying new machines until the HD models become cheaper (and hopefully reliable).

The lack of EPG is still annoying, but I can live with it.

My heartfelt thanks to tghewett, who has been prompt and helpful with his advice.

Colin.

I've been given a 10gb IDE 2.5 drive so I thought I would try it out to see if it cured the picture freezing and the sound glitches. The 4000 had already had all the caps replaced and the connection between the psu and main board directly soldered istead of using the mutipin connecting lead and plugs.

Unfortunately watching BBC1 there were still some problems. It was similar to result that MGPA reported. It's not good enough for me to use and anyway we are used to the Humax 9200 I bought as a relacement now. It will have to go back in the loft until I can bring myself to ditch it!.