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Stuck on Tune - Try This


Inactive User
Nov 4, 2005
hi guys found this posted on another forum sounds very interesting, credit goes to grizzlyGaz for the post.

Stuck On Tune

it seems that when the CC's roll a software update, loads of peeps get stuck in tune problems with 4001's.

So I had a bash at a few which were suffering this to get them out, and had a fair bit of success.

What I did was used a Maxview single set TV amplifier (it does UHF and VHF), and it is adjustable gain (has a knob on it to adjust the gain up and down blah blah).

I opened up the boxes, removed the CIM unit (the unit where the talkback is cut), and connected the output of the Maxview amplifier directly to the FRONT tuner (the tuner nearest the front of the box).
Obviously, the cable signal is connected to the input of the amplifier.
I then powered the box on, adjusted the gain up and down on the amplifier until hey presto...box goes into update and comes out of tune.

What I did find, was that some boxes needed low gain on the amp, some higher so its a case of fidgeting around until the box takes.

It was interesting to watch the picture on the box whilst running like this, the box works 100%, and then you back of the gain slightly and maybe the piccy's start to freeze and block, and in some cases this was ONLY JUST below the signal where the boxx took the hit and updated, seems that strong signals is not always a good thing for these boxes and can cause problems (maybe the Paces have a naff AGC system ?).

Anyway, what I also found with this is that it showed me one box had a naff CIM unit as when the CIM was put back in, the box still stayed stuck in tune, whereas running directly fed from the maxview amp it worked 100%, changing this unit made that box happy again.

Although I havent measured the signal levels exiting the maxview amps, it seems that when theyre turned down, they can make the box freeze etc. so the box obviously isnt getting enough signal, therefore I can only assume that the CIM unit is also an amplifier ? (never read any specs on exeactly what those units do). Looks like using an amplifier in this way gives you a variable gain CIM unit which allows you to get the best signal match for your box to the cable system signal at your location, thus getting past problems that come from a mismatch.

Hope this little trick will get some of you going again with your stuck in tunes, I guess in many cases, just connecting a similar adjustable amp inline on the cable to your box and having a fiddle without taking anything apart and removing the CIM will do just as good a job, but of you have a naff CIM, you wont know until its bypassed.

Best of liuck !


DW Member ++
May 5, 2005
this is cobblers LOL - a 4001 will not come out of tune at all with this configuration < never mind take an update....

since when did a uhf tv amplifier ramp up a signal in the 800mhz-1ghz range.

this might work on a 1000 box IT WILL NOT WORK ON A 4001.


DW Member ++
Nov 21, 2001
hahaha, it seems if he had changed the cim in the 1st place "he wouldent be arseing about with a signal booster"