What am i doing wrong?

[jbivy]

So ive a 1956 packard bell (i think its a model 24s as thats what the back says, the interior says its an 8851 tube layout). Ive recapped it, did them one at a time, so its correct. Checked the tubes and replaced the ones that were low. Had my uncle check it out, he used to be a tv repairman, he saw no solder spalshes, nothing.

When i turn it on it gets a picture for about ten seconds, crystal clear one at that, then it goes to a horizontal line and then a dot and dissapears.

Im a novice so.. what should i be checking? Ive yet to find a sams for this or well..much on it at all.